WO2025077547A1

WO2025077547A1 - Luminescent tetradentate ligand gold (iii) compounds for organic light-emitting devices and their preparation

Info

Publication number: WO2025077547A1
Application number: PCT/CN2024/120085
Authority: WO
Inventors: Vivian Wing-Wah Yam; Ka Wai KWONG; Mei-Yee Chan; Yiu-Wing Wong
Original assignee: University of Hong Kong HKU
Current assignee: University of Hong Kong HKU
Priority date: 2023-10-09
Filing date: 2024-09-20
Publication date: 2025-04-17
Anticipated expiration: 2026-04-09
Also published as: TW202530234A

Abstract

A series of highly rigid and highly luminescent cyclometalated tetradentate ligand-containing gold (III) compounds is designed and synthesized. The cyclometalated tetradentate ligand-containing gold (III) compounds can be used as light-emitting material for fabrication of light-emitting devices. The cyclometalated tetradentate ligand-containing gold (III) compounds can be deposited as a layer or a component of a layer using a solution-processing technique or a vacuum deposition process. The cyclometalated tetradentate ligand-containing gold (III) compounds are robust and can provide electroluminescence with high efficiency and brightness. More importantly, vacuum-deposited OLEDs demonstrate high operational stabilities with long operational half-lifetimes of over 188,000 hours at 100 cd m^-2.

Description

LUMINESCENT TETRADENTATE LIGAND GOLD (III) COMPOUNDS FOR ORGANIC LIGHT-EMITTING DEVICES AND THEIR PREPARATION

FIELD OF THE INVENTION

The disclosed invention is generally in the field of luminescent cyclometalated tetradentate gold (III) compounds, methods of making and of using thereof, particularly cyclometalated tetradentate C^N^C^N ligands coordinated to a gold (III) metal center, a facile method of making, and the use of these compounds in organic light-emitting devices (OLEDs) , such as vacuum-deposited OLEDs and solution-processed OLEDs.

BACKGROUND OF THE INVENTION

Taking the advantages of low cost, light weight, low power consumption, high brightness, excellent color tunability, wide viewing angle of up to 180 degrees as well as their ease of fabrication onto flexible substrates, organic light-emitting devices (OLEDs) are considered as remarkably attractive candidates for flat panel displays and solid-state lighting systems. Compared with the pure organic counterparts, transition metal complexes have been extensively studied over the past three decades due to the presence of the heavy metal center, which can effectively lead to a strong spin-orbit coupling and thus promote an efficient intersystem crossing to harvest triplet excitons for generating phosphorescence. This can theoretically result in a four-fold enhancement in the internal quantum efficiency (IQE) of the OLEDs up to 100 %when compared to fluorescence singlet emitters (IQE = 25 %) due to the harvesting of all triplet and singlet excitons. Typically, an OLED is made of several layers of semiconductors sandwiched between two electrodes. The cathode is composed of a low work function metal or metal alloy deposited by vacuum evaporation, whereas the anode is a transparent conductor such as indium tin oxide (ITO) . Upon the application of a direct current (DC) voltage, holes injected by the ITO anode and electrons injected by the metal cathode will recombine to form excitons. Subsequent relaxation of excitons will then result in the generation of electroluminescence (EL) .

The EL from organic materials was first discovered in anthracene crystals immersed in liquid electrolyte in 1965 [Helfruch, W.; Schneider. W.G. Phys. Rev. Lett. 14, 229 (1965) ] . Although a lower operating voltage could be achieved by using a thin film of anthracene with solid electrodes, very low efficiencies were encountered with these single-layer devices. Meanwhile, EL from organic polymers was initially reported in the 1970s [Kaneto, K.; Yoshino, K.; Koa, K.; Inuishi, Y. Jpn. J. Appl. Phys. 13, 1023 (1974) ] , where green emission from polyethylene terephthalate was observed when an impulse voltage was applied. The breakthroughs that led to the exponential growth of this field and to its first commercialized products can be traced to two successful demonstrations. Tang and VanSlyke proposed the use of a double-layer structure of vacuum deposited, small-molecular films, in which tris (8-hydroxyquinoline) aluminum (Alq₃) was utilized both as light-emitting layer and electron transporting layer [Tang, C.W.; VanSlyke, S.A. Appl. Phys. Lett. 51, 913 (1987) ] . Later, the first polymeric light-emitting device was developed by Burroughs et al. in 1990 [Burroughs, J.H.; Bradley, D.D.C.; Brown, A.R.; Marks, N.; Friend, R.H.; Burn, P.L.; Holmes, A.B. Nature 347, 539 (1990) ] , in which a yellow-green EL from poly (p-phenylenenvinylene) (PPV) was achieved. Since then, a number of new electroluminescent small molecular and polymeric light-emitting materials have been investigated with improved light-emitting properties. The key advantage of using polymers as light-emitting materials is their high solubility in most of the common organic solvents, and thus OLEDs can be easily fabricated by using low-cost and efficient wet processing techniques, such as spin-coating, screen-printing, or ink-jet printing [Burrows, P.E.; Forrest, S.R.; Thompson, M.E. Curr. Opin. Solid State Mat. Sci. 2, 236 (1997) ] .

In 1998, Baldo et al. demonstrated an efficient phosphorescent OLED (PHOLED) with high IQE by using platinum (II) 2, 3, 7, 8, 12, 13, 17, 18-octaethyl-21H, 23H-porphyrin (PtOEP) as a dopant [Baldo, M.A.; O’ Brien, D.F.; You, Y.; Shoustikow, A.; Sibley, S.; Thompson, M.E.; Forrest, S.R. Nature 395, 151 (1998) ; O’ Brien, D.F.; Baldo, M.A.; Thompson, M.E.; Forrest, S.R. Appl. Phys. Lett. 74, 442 (1999) ] . Such multilayer device consisted of an emitting layer of Alq₃ doped with PtOEP and showed a strong emission at 650 nm arising from the triplet excitons of PtOEP. Since then, a large number of metal complexes have been demonstrated with excellent photophysical properties. Particularly, cyclometalated iridium (III) compounds are one of the most widely investigated classes of metal complexes. Most of the cyclometalated iridium (III) complexes show intense phosphorescence and have been extensively investigated for the fabrication of high efficiency OLEDs. Of particular interest is the development of iridium (III) complexes with 2-phenylpyridine ligand (s) . In 1999, Thompson, Forrest and co-workers have demonstrated more efficient PHOLEDs based onfac-tris (2-phenylpyridine) iridium (III) [Ir (ppy) ₃] as phosphorescent emitting material doped in a 4, 4′ -N, N′ -dicarbazole-biphenyl (CBP) host [Baldo, M.A.; Lamansky, S.; Burrows, P.E.; Thompson. M.E.; Forrest, S.R. Appl. Phys. Lett. 75, 4 (1999) ] . Another successful iridium (III) complex is sky-blue-emitting iridium (III) bis [2- (4′ , 6′ -difluorophenyl) pyridinato-N, C²] -picolinate [FIr (pic) ] , which exhibits a higher photoluminescence quantum yield (PLQY) of about 60 %in solution and nearly 100 %in a solid-state thin film when doped into a high triplet energy host [Rausch, A.F.; Thompson, M.E.; Yersin, H. Inorg. Chem. 48, 1928 (2009) ; Adachi, C; Kwong, R.C.; Djurovich, P.I.; Adamovich, V.; Baldo, M.A.; Thompson, M.E.; Forrest, S.R. Appl. Phys. Lett. 79, 2082 (2001) ; Kawamura, Y.; Goushi, K.; Brooks, J.; Brown, J.J.; Sasabe, H.; Adachi, C. Appl. Phys. Lett. 86, 071104 (2005) ] . Highly efficient OLEDs with external quantum efficiencies (EQEs) of up to 30 %have recently been demonstrated based on the iridium (III) systems [Kim, S.-Y.; Jeong, W.-I.; Mayr, C.; Park, Y.-S.; Kim, K.-H.; Lee, J.-H.; Moon, C.-K.; Brütting, W.; Kim, J.-J. Adv. Funct. Mater. 23, 3829 (2013) ; Udagawa, K.; Sasabe, H.; Igarashi, F.; Kido, J. Adv. Opt. Mater. 4, 86 (2015) ] .

Apart from the iridium (III) systems with d⁶ electronic configuration and octahedral geometry, the coordination-unsaturated nature of d⁸ transition metal complexes with square-planar structures has been found to provide intriguing spectroscopic and luminescence properties related to the unique tendency of these metal centers to exhibit non-covalent metal…metal interactions. Of particular interest is the platinum (II) compounds due to their rich luminescence properties, associated with their strong propensity to from Pt…Pt and π-πinteractions. Notably, unlike the case of the iridium (III) systems, the use of bidentate cyclometalated ligands will not lead to isomerization during synthesis or sublimation. Moreover, further stabilization of these platinum (II) complexes can be accomplished through the use of tridentate and tetradentate ligands to give highly robust metal complex systems. To date, highly efficient OLEDs with power efficiencies of up to 126 lm W^-1 and EQEs of up to 26.5 %have been achieved [Cheng, G.; Kui, S. C.-F.; Ang, W.-H.; Ko, M.-Y.; Chow, P.-K.; Kwong, C.-L.; Kwok, C.-C.; Ma, C.; Guan, X.; Low, K.-H.; Su, S.-J.; Che, C.-M. Chem. Sci. 5, 4819 (2014) ] . In contrast to the isoelectronic platinum (II) compounds, luminescent gold (III) complexes are relatively less explored, probably due to the presence of low-energy d-d ligand field (LF) states and the electrophilicity of the gold (III) metal center. It is difficult to coordinate cyclometalating tetradentate ligands to the gold (III) metal center through successive C-H activations, unlike the case for the isoelectronic platinum (II) complexes where cyclometalating tetradentate ligands can be readily incorporated into the platinum (II) center via one-pot reaction. Thus, there is a need to design gold (III) complexes that have more enhanced photophysical properties and involve less steps during synthesis. In 2017, Yam and co-workers have overcome this challenge by using post-synthetic modification, where the alkynyl ligand and the tridentate pincer ligand were covalently linked together through palladium-catalyzed Buchwald-Hartwig amination [Wong, B. Y.-W.; Wong, H.-L.; Wong, Y.-C.; Chan, M.-Y.; Yam, V. W.-W. Angew. Chem. Int. Ed. 56, 302 (2017) ] . The team has further developed another new class of tetradentate ligand-containing gold (III) complexes by using one-pot two bond-forming reaction, where the bifunctional gold (III) precursor with complementary bifunctional aromatic moiety were coupled [Lee, C.-H; Tand, M.-C.; Kong, F. K.-W; Cheung, W.-L.; Ng, M.; Chan, M.-Y.; Yam, V. W.-W. J. Am. Chem. Soc. 142, 520 (2020) ] . However, these tetradentate ligand-containing gold (III) complexes are unable to be thermally evaporated and only solution-processed OLEDs could be prepared. Accordingly, there remains a need to develop tetradentate ligand-containing gold (III) complexes with improved properties.

Therefore, it is an object of the present invention to develop tetradentate ligand-containing gold (III) complexes with improved luminescence properties and/or processability.

SUMMARY OF THE INVENTION

This class of gold (III) compounds have excellent chemical and thermal stabilities, in which they can be utilized for preparing uniform thin films by either vacuum deposition and/or spin-coating technique. This is not the case for other previously reported tetradentate C^N^C^N ligand-containing gold (III) complexes, where they are not thermally evaporable. These distinct properties of the present tetradentate C^N^C^N gold (III) complexes provide great opportunities to realize high performance vacuum-deposited OLEDs with high EQEs and long operational half-lifetimes at 100 cd m^-2. The materials disclosed represent for the first time vacuum-deposited OLEDs based on tetradentate C^N^C^N ligand-containing gold (III) complexes having long operational lifetimes. These performances are also comparable to the state-of-the-art OLEDs based on iridium (III) complexes and thermally activated delayed fluorescence (TADF) materials.

The present disclosure provides a class of luminescent gold (III) compounds having the chemical structure shown in the generic formula (I) :

wherein:

(a) ring A is coordinated to the Au atom through a nitrogen atom, and contains a substituted or unsubstituted pyridyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted thienopyridinyl, a substituted or unsubstituted furopyridinyl group, a substituted or unsubstituted selenophenopyridinyl group;

(b) rings B and B’ are each coordinated to the Au atom through a carbon atom, and are each independently a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;

(c) each D is independently at each occurrence absent or a cyclic or acyclic moiety wherein: (ci) the cyclic moiety is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted polycyclic group, a substituted or unsubstituted acene, and a substituted or unsubstituted a heteroacene; and (cii) the acyclic moiety is selected from the group consisting of a substituted or unsubstituted alkynyl, a substituted or unsubstituted arylalkynyl, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted alkoxy, and a substituted or unsubstituted arylalkoxy;

(d) the dashed curved line in ring E is absent or present, wherein if the dashed curved line in ring E is absent, there is no bond connection between the ring structures D; if the dashed curved line in ring E is present, ring E is a substituted or unsubstituted N-containing ring with ring size of 5-10 that may contain either one or more chemical moieties selected from -C (RR′ ) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′ ) -, -Se-, -As (R) , -CH=CH-and -CR=CR′ -, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, thioether, selenoether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(e) the dashed linear lines independently represent the absence or presence of a bond; B, B’ , and each D, independently represent a substituted or unsubstituted monocyclic aryl, a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) , or a substituted or unsubstituted heteroaryl group; or D, Y, and B together and/or D, Y, and B’ together, independently form a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) ; X and Y are each independently at each occurrence absent or non-coordination sites selected from the group consisting of -C (RR′ ) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′ ) -, -Se-, -As (R) , -CH=CH-and -CR=CR′ -, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonateester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(f) whereinp and q are each independently 0, 1, 2 or 3; andp and q are not both equal to 0. Whenp or q is equal to 0, there is no bond connection between the ring structures B and D, or B′ and D. When Y is absent andp or q is equal to 1, there is a single bond linked between the ring structures B and D, or B′ and D, respectively. When Y is present andp or q is equal to 1, there is a single bond linked between Y and the ring structures B and D, or B′ and D;

(g) wherein r and s are each independently 1, 2 or 3. When X is absent and s or r is equal to 1, there is a single bond linked between the ring structures A and B′ , or A and B. When X is present and s or r is equal to 1, there is a single bond between X and the ring structures A and B′ , or A and B;

(h) Z and Z’ are each a substituent on Ring B and B′ , respectively, and are each independently selected from the group consisting of substituted or unsubstituted alkyl (e.g., substituted or unsubstituted C₁-C₁₀ alkyl) , substituted or unsubstituted haloalkyl (e.g., substituted or unsubstituted C₁-C₁₀ haloalkyl) , substituted or unsubstituted amine, substituted or unsubstituted alkoxy (e.g., substituted or unsubstituted C₁-C₁₀ alkoxy) , substituted or unsubstituted haloalkoxy (e.g., substituted or unsubstituted C₁-C₁₀ haloalkoxy) , substituted or unsubstituted alkylthio (e.g., substituted or unsubstituted C₁-C₁₀ alkylthio) , substituted or unsubstituted alkylselenyl (e.g., substituted or unsubstituted C₁-C₁₀ alkylselenyl) , hydroxyl, thiol, nitrile, nitro, F, Cl, Br, and I, and g and g’ are independently an integer between 1 and 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; wherein when g or g’ is equal to 0, the substituent Z or Z’ , respectively, is absent;

(i) n is zero, a positive integer or a negative integer.

In certain embodiments, the gold (III) compound is deposited as a thin layer on a substrate layer.

In certain embodiments, the gold (III) compound contains a thin layer that is prepared by vacuum deposition, spin-coating, or inkjet printing.

In certain embodiments, the gold (III) compound has photoluminescence (PL) properties within a range of about 380 to 1500 nm.

In certain embodiments, the gold (III) compound emits light in response to the passage of an electric current or to a strong electric field.

In certain embodiments, the gold (III) compound is used to fabricate an OLED.

In certain embodiments, the gold (III) compound serves as the light-emitting layer of the OLED.

In certain embodiments, the gold (III) compound serves as a dopant in the light-emitting layer or emissive layer of the OLED.

In certain embodiments, the gold (III) compound serves as a sensitizer in the light-emitting layer or emissive layer of the OLED.

In certain embodiments, the gold (III) compound serves as a carrier-transporting material in the light-emitting layer or emissive layer of the OLED.

In certain embodiments, the light-emitting layer or emissive layer is prepared using vacuum deposition or solution processing technique.

Disclosed herein is a method for preparing a luminescent compound with cyclometalated tetradentate ligand involving the following reaction:

wherein:

(a) R¹, R², R³, R⁴ and R⁵ groups are each independently selected from the group consisting of OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, CF₃, OCF₃, NO₂, SO₂, SOR, SO₃R, halo, or alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl with one or more alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl being optionally substituted with one or more OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, CF₃, OCF₃, NO₂, SO₂, SOR, SO₃R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or a heterocyclic group, wherein R is independently alkyl, alkynyl, alkylaryl, aryl or cycloalkyl; and

(b) G is selected from the group consisting of BR₂, CR, CRR′ , C (O) , C (O) R, C (O) OR, C (O) NR₂, O, NR, S, SR, SO₂, SOR, Si, P, P (=O) , S, Se or alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl with one or more alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl being optionally substituted with one or more OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, CF₃, OCF₃, NO₂, SO₂, SOR, SO₃R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or a heterocyclic group, wherein R is independently alkyl, alkynyl, alkylaryl, aryl or cycloalkyl; and

(c) n is zero, a positive integer or a negative integer.

In certain embodiments, a luminescent compound is prepared as described above. Preferably, in one or more embodiments, a new class of gold (III) complexes with tetradentate ligands that can be obtained from a simple one-pot reaction is provided. Particularly, the disclosed compounds can be prepared by Suzuki-Miyaura cross-coupling followed by Buchwald-Hartwig cross-coupling of the gold (III) precursor complex and the precursor ligand, with intramolecular cyclization occurring spontaneously to generate the gold (III) complexes with tetradentate ligands in one pot. This can significantly increase the ease of preparation and reduction in the number of steps for synthesis and purification, as well as improve the product yield. The more rigid tetradentate ligand framework can effectively rigidify the molecule and reduce the non-radiative decay, and thus improve the chemical and thermal stabilities of the claimed gold (III) complexes, as exemplified by their high decomposition temperatures of around 420℃. In addition, the emission color of the tetradentate gold (III) complexes can be effectively tuned by changing the N-donor atoms on the cyclometalating tetradentate ligand. This provides avenues to fabricate the devices by either vacuum deposition or solution-processing techniques, such as spin-coating and ink-jet printing. High performance vacuum-deposited and solution-processed OLEDs have been demonstrated. More importantly, vacuum-deposited devices show satisfactory high operational stabilities with long operational half-lifetimes at 100 cd m^-2. This disclosure involves important energy and environmental implications through the exploration of new classes of robust gold (III) complexes with tetradentate ligands for the OLED display and solid-state lighting industries.

In certain embodiments, the tetradentate gold (III) compound is included in a light-emitting layer of a light-emitting device

In certain embodiments, the tetradentate gold (III) compound is included in a layer of a light-emitting device.

In certain embodiments, the tetradentate gold (III) compound is a dopant included in the light-emitting layer or emissive layer of the light-emitting device.

In certain embodiments, the tetradentate gold (III) compound is a dopant included in a light-emitting device.

Provided in this disclosure is a light-emitting device with an ordered structure containing an anode, a hole-transporting layer, a light-emitting layer, an electron-transporting layer and a cathode wherein the light-emitting layer comprises a gold (III) compound having a chemical structure represented by formula (I) , as described above.

Provided in this disclosure is an apparatus containing: a compound of formula (I) disclosed herein. The apparatus can be a television, a copier, a printer, a liquid crystal display, a measuring instrument, a display board, a marker lamp, an electrophotographic photoreceptor, a photoelectric transducer, a solar cell or an image sensor, such that the apparatus incorporates the compound for light emission purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the basic structure of an organic EL device, in accordance with one or more embodiments herein.

FIG. 2 shows the UV-visible absorption spectra of compounds 1-5 in dichloromethane at 298 K, in accordance with one or more embodiments herein.

FIG. 3 shows the normalized PL spectra of compounds 1-4 in dichloromethane at 298 K, in accordance with one or more embodiments herein.

FIG. 4 shows the normalized PL spectra of thin films of compounds 1-4 doped into MCP at 5 wt%at 298 K, in accordance with one or more embodiments herein.

FIG. 5 shows the solid-state thin film emission spectra of compound 1 doped into MCP at 5, 10, 15 and 20 wt%at 298 K, in accordance with one or more embodiments herein.

FIG. 6 shows the normalized EL spectra of the solution-processed devices made with compound 1 doped at different concentrations.

FIG. 7 shows the EQEs of the solution-processed devices made with compound 1 as a function of current density doped at different concentrations.

FIG. 8 shows the normalized EL spectra of the solution-processed devices made with compound 2 doped at different concentrations.

FIG. 9 shows the EQEs of the solution-processed devices made with compound 2 as a function of current density doped at different concentrations.

FIG. 10 shows the normalized EL spectra of the solution-processed devices made with compound 3 doped at different concentrations.

FIG. 11 shows the EQEs of the solution-processed devices made with compound 3 as a function of current density doped at different concentrations.

FIG. 12 shows the normalized EL spectra of the vacuum-deposited devices made with compound 1 doped at different concentrations.

FIG. 13 shows the EQEs of the vacuum-deposited devices made with compound 1 as a function of current density doped at different concentrations.

FIG. 14 shows the normalized EL spectra of the vacuum-deposited devices made with compound 2 doped at different concentrations.

FIG. 15 shows the EQEs of the vacuum-deposited devices made with compound 2 as a function of current density doped at different concentrations.

FIG. 16 shows the normalized EL spectra of the vacuum-deposited devices made with compound 3 doped at different concentrations.

FIG. 17 shows the EQEs of the vacuum-deposited devices made with compound 3 as a function of current density doped at different concentrations.

FIG. 18 shows the normalized EL spectra of the vacuum-deposited devices made with compound 4 doped at different concentrations.

FIG. 19 shows the EQEs of the vacuum-deposited devices made with compound 4 as a function of current density doped at different concentrations.

FIG. 20 shows the relative luminance of vacuum-deposited devices made with compounds 1-3 as a function of time.

DETAILED DESCRIPTION OF THE INVENTION

I. Definitions

The term “halo” or “halogen” or “halide” as used herein includes fluorine, chlorine, bromine and iodine.

The term “pseudohalide” as used herein includes, but are not limited to, cyanate, thiocyanate and cyanide.

The term “alkyl” as used herein includes straight and branched chain alkyl groups. Preferred alkyl groups are those containing between one to eighteen carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and other similar compounds. In addition, the alkyl group may be optionally substituted with one or more substituents selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkenyl” as used herein includes both straight and branched chain alkene radicals. Preferred alkenyl groups are those containing between two and eighteen carbon atoms. In addition, the alkenyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkynyl” as used herein includes both straight and branched chain alkyne radicals. Preferred alkynyl groups are those containing between two and eighteen carbon atoms. In addition, the alkynyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkylaryl” as used herein includes an aryl group which has an alkyl group as a substituent. In addition, the alkylaryl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkenylaryl” as used herein includes an aryl group which has an alkenyl group as a substituent. In addition, the alkenylaryl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkynylaryl” as used herein includes an aryl group which has an alkynyl group as a substituent. In addition, the alkynylaryl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkylalkenyl” as used herein includes an alkenyl group which has an alkynyl group as a substituent. In addition, the alkylalkenyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “arylalkenyl” as used herein includes an alkenyl group has an aryl group as a substituent. In addition, the arylalkenyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkynylalkenyl” as used herein includes an alkenyl group which has an alkynyl group as a substituent. In addition, the alkynylalkenyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkylalkynyl” as used herein includes an alkynyl group which has an alkyl group as a substituent. In addition, the alkylalkynyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “arylalkynyl” as used herein includes an alkynyl group which has an aryl group as a substituent. In addition, the arylalkynyl group may be optionally substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “cycloalkyl” as used herein includes cyclic alkyl groups. Cycloalkyl groups can contain 3 to 7 or more carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, and the like. Cycloalkyl group can be unsubstituted or substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “alkoxy” or “alkyloxy” as used herein interchangeably includes linear or branched alkyl group of 1 to 18 or more carbon atoms bonded to an oxy (O) group, and unsubstituted or substituted with one or more substituents including alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, aryl ether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, NRR' , SR, C (O) R, COOR, C (O) NR, SOR, SOR, BRR' and derivatives thereof; and R and R' are independently selected from the group consisting of hydrogen atom, deuterium atom, formaldehyde, cyano, alkylalkynyl, substituted alkylalkynyl, arylalkynyl, substituted arylalkynyl, heteroarylalkynyl, substituted heteroarylalkynyl, condensed polycyclic, substituted condensed polycyclic, aryl, alkyl, heteroaryl, nitro, trifluoromethane, cyano, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and derivatives thereof.

The term “aryl, ” alone or in combination, includes carbocyclic aromatic systems. The systems may contain one, two or three rings wherein each ring may be attached together in a pendant manner or may be fused. For example, the rings can be 5-or 6-membered rings. Aryl groups include, but not exclusive to, unsubstituted or substituted derivatives of benzene (phenyl) , naphthylene, pyrene, anthracene, pentacene, benzo [a] pyrene, chrysene, coronene, corannulene, naphthacene, phenanthrene, triphenyklene, ovalene, benzophenanthrene, perylene, benzo [g, h, i] perylene, antanthrene, pentaphene, picene, dibenzo [3, 4: 9, 10] pyrene, benzo [3, 4] pyrene, dibenzo [3, 4: 8, 9] pyrene, dibenzo [3, 4; 6, 7] pyrene, dibenzo [1, 2: 3, 4] pyrene, and naphto [2, 3; 3, 4] pyrene; wherein the positions of attachment and substitution can be at any carbon of the group that does not sterically inhibit formation of compound of formula (I) , as can be appreciated by one skilled in the art.

The term “heteroaryl, ” alone or in combination, includes heterocyclic aromatic systems. The systems may contain one, two or three rings wherein each ring may be attached together in a pendant manner or may be fused. For example, the rings can be 5-or 6-membered rings. Heterocyclic and heterocycle refer to a 3 to 7-membered ring containing at least one heteroatom. Heteroaryl groups include, but not exclusive to, unsubstituted or substituted derivatives of pyridine, thiophene, furan, pyrazole, imidazole, oxazole, isoxazole, thiazole, isothiazole, pyrole, pyrazine, pyridazine, pyrimidine, benzimidazole, benzofuran, benzothiazole, benzopyrrolizinophenoxazine, indolocarbazole, oxadiazole, thiadiazole, indole, triazole, tetrazole, pyran, thiapyran, oxadiazole, triazine, tetrazine, carbazole, dibenzothiophene, dibenzofuran, isoindole, quinoline, isoquinoline, chromene, isochromene, thienopyridine, furopyridine, selenophenopyridine, and non-aromatic rings piperazine, piperidine, pyrolidine and thereof; wherein the position of attachment or substitution can be at any carbon of the group that does not sterically inhibit formation of compound of formula (I) , as can be appreciated by one skilled in the art.

The terms “heterocyclic” and “heterocycle” refer to a 3 to 7-membered non-aromatic ring containing at least one heteroatom, and includes piperazine, piperidine, pyrrolidine, morpholine, thiomorpholine, pyran, thiopyran, dihydrofuranyl, tetrahydrofuranyl, dihydrothiophenyl, tetrahydrothiophenyl, dihydropyranyl, tetrahydropyranyl, dihydrothiazolyl and the like. The groups of the present disclosure can be substituted or unsubstituted. Preferred substituents include but are not limited to alkyl, alkoxy, aryl.

The term “heteroatom” as used herein includes S, O, N, P, Se, Te, As, Sb, Bi, B, Si, Ge, Sn and Pb.

The term “substituted” refers to any level of substitution although mono-, di-and tri-substitutions are preferred. Substituents including hydrogen, halogen, aryl, alkyl, heteroaryl, nitro group, trifluoromethane group, cyano group, arylether, alkylether, heteroarylether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, oxadiazole, thiadiazole, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic group and thereof, that are readily prepared.

Benzene includes substituted or unsubstituted benzene. Pyridine includes substituted or unsubstituted pyridine. Thiophene includes substituted or unsubstituted thiophene. Furan includes substituted or unsubstituted furan. Pyrazole includes substituted or unsubstituted pyrazole. Imidazole includes substituted or unsubstituted imidazole. Oxazole includes substituted or unsubstituted oxazole. Isoxazole includes substituted or unsubstituted isoxazole. Thiazole includes substituted or unsubstituted thiazole. Isothiazole includes substituted or unsubstituted isothiazole. Pyrrole includes substituted or unsubstituted pyrole. Pyrazine includes substituted or unsubstituted pyrazine. Pyridazine includes substituted or unsubstituted pyridazine. Pyrimidine includes substituted or unsubstituted pyrimidine. Benzimidazole includes substituted or unsubstituted benzimidazole. Benzofuran includes substituted or unsubstituted benzofuran. Benzothiazole includes substituted or unsubstituted benzothiazole. Indole includes substituted or unsubstituted indole. Naphthalene includes substituted or unsubstituted naphthalene. Triazole includes substituted or unsubstituted triazole. Tetrazole includes substituted or unsubstituted tetrazole. Pyran includes substituted or unsubstitutedpyran. Thiapyran includes substituted or unsubstituted thiapyran. Oxadiazole includes substituted or unsubstituted oxadiazole. Triazine includes substituted or unsubstituted triazine. Tetrazine includes substituted or unsubstituted tetrazine. Carbazole includes substituted or unsubstituted carbazole. Dibenzothiophene includes substituted or unsubstituted dibenzothiophene. Dibenzofuran includes substituted or unsubstituted dibenzofuran. Piperazine includes substituted or unsubstituted piperazine. Piperidine includes substituted or unsubstituted piperidine. Pyrrolidine includes substituted or unsubstituted pyrolidine. Indolocarbazole includes substituted or unsubstituted indolocarbazole. Benzopyrrolizinophenoxazine includes substituted or unsubstituted benzopyrrolizinophenoxazine. Thiadiazole includes substituted or unsubstituted thiadiazole.

II. Compositions

Embodiments of the subject matter described herein involve thermally stable gold (III) compounds containing rigid tetradentate ligands. Other embodiments of the subject matter described herein involve the modification of luminescent tetradentate ligand-containing gold (III) compounds. The luminescent gold (III) compounds contain a tetradentate ligand containing four ligating sites coordinated to a gold (III) metal center. The ligation site is composed of coordinating atoms that can be, for example, nitrogen, carbon, or σ-donating groups, for example, aryl groups, heteroaryl groups.

The luminescent tetradentate ligand-containing gold (III) compounds contain:

at least one gold metal center having a +3 oxidation state and four coordination sites;

a tetradentate ligand bearing coordinating atoms as ligating site to coordinate to the gold center; and the coordinating sites are connected directly or via an aromatic system or spacer to form a rigid tetradentate ligand having four coordination sites.

The luminescent gold (III) compounds exhibit high PLQY in solid-state thin films, and have been demonstrated to serve as phosphorescent dopants in the fabrication of vacuum-deposited and solution-processed OLEDs. The gold (III) compounds disclosed herein, when implemented in a high-performance vacuum-deposited and solution-processed OLEDs, produce superior EL with high EQEs. The compounds disclosed herein produce better performances than those of vacuum-deposited and solution-processed red-emitting OLEDs reported based on cyclometalated gold (III) complexes and thermally activated delayed fluorescence (TADF) materials. More importantly, vacuum-deposited OLEDs show satisfactory high operational stabilities with long operational half-lifetimes of up to 188,000 h at 100 cd m^-2. The disclosed subject matter provides new classes of phosphors for the OLED display and solid-state lighting industries that can be fabricated by using low-cost and high efficiency solution-processing techniques to obtain PHOLEDs.

The new class of gold (III) compounds described herein further shows either strong PL via a triplet excited state upon photo-excitation, or EL via a triplet exciton upon applying a voltage. According to one or more embodiments herein, these gold (III) compounds are highly soluble in common organic solvents such as dichloromethane, chloroform and toluene. Alternatively, the compounds can be doped into a host matrix for thin film deposition by spin-coating or ink-jet printing or other known fabrication methods. In one or more embodiments, the compounds can be used for the fabrication of OLEDs as phosphorescent emitters or dopants to generate EL.

While the gold (III) compounds described herein are described with use in OLEDs, the compounds have additional applications as would be understood to those who are skilled in the art. The gold (III) compounds described herein have strong light-emitting and light absorption properties that make them suitable for inclusion into common apparatuses for which light emission or absorption are desired. For example, the gold (III) compounds may be used as, but not limited to, the backlighting of flat panel displays of wall-mounted televisions, copiers, printers, liquid crystal displays, measuring instruments, display boards, marker lamps, electrophotographic photoreceptors, photoelectric transducers, solar cells, image sensors, medical display, medical devices and imaging devices.

The luminescent tetradentate ligand-containing gold (III) compounds have the chemical structure shown in formula (I) ,

wherein:

(e) the dashed linear lines independently represent the absence or presence of a bond; B, B’ , and each D, independently represent a substituted or unsubstituted monocyclic aryl, a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) , or a substituted or unsubstituted heteroaryl group; or D, Y, and B together and/or D, Y, and B’together, independently form a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) ; X and Y are each independently at each occurrence absent or non-coordination sites selected from the group consisting of -C (RR′ ) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′ ) -, -Se-, -As (R) , -CH=CH-and -CR=CR′ -, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonateester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(f) whereinp and q are each independently 0, 1, 2 or 3; andp and q are not both equal to 0. Whenp or q is equal to 0, there is no bond connection between the ring structures B and D, or B′ and D. When Y is absent andp or q is equal to 1, there is a single bond linked between the ring structures B and D, or B′ and D, respectively. When Y is present andp or q is equal to 1, there is a single bond between Y and the ring structures B and D, or B′ and D;

(h) Z and Z’ are each a substituent on Ring B and B′ , respectively, and are each independently selected from the group consisting of substituted or unsubstituted alkyl (e.g., substituted or unsubstituted C₁-C₁₀ alkyl) , substituted or unsubstituted haloalkyl (e.g., substituted or unsubstituted C₁-C₁₀ haloalkyl) , substituted or unsubstituted amine, substituted or unsubstituted alkoxy (e.g., substituted or unsubstituted C₁-C₁₀ alkoxy) , substituted or unsubstituted haloalkoxy (e.g., substituted or unsubstituted C₁-C₁₀ haloalkoxy) , substituted or unsubstituted alkylthio (e.g., substituted or unsubstituted C₁-C₁₀ alkylthio) , substituted or unsubstituted alkylselenyl (e.g., substituted or unsubstituted C₁-C₁₀ alkylselenyl) , hydroxyl, thiol, nitrile, nitro, F, Cl, Br, and I, and g and g’ are independently an integer between 1 and 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; wherein when g or g’ is equal to 0, the substituent Z or Z’ , respectively, is absent; and

(i) n is zero, a positive integer or a negative integer.

In some forms, the compound is as described above for Formula I, except that ring A is an unsubstituted pyridyl group, an unsubstituted isoquinolinyl group, an unsubstituted quinolinyl group, an unsubstituted pyrazinyl group, an unsubstituted pyrimidinyl group, an unsubstituted triazinyl group, an unsubstituted carbolinyl group, an unsubstituted thienopyridinyl, an unsubstituted furopyridinyl group, or an unsubstituted selenophenopyridinyl group.

In some forms, the compound is as described above for Formula I, except that ring A contains a substituted pyridyl group, a substituted isoquinolinyl group, a substituted quinolinyl group, a substituted group, a substituted pyrimidinyl group, a substituted triazinyl group, a substituted carbolinyl group, a substituted thienopyridinyl, a substituted furopyridinyl group, or a substituted selenophenopyridinyl group.

When ring A contains a substituted group, as described herein, ring A is preferably substituted with an unsubstituted phenyl, tert-butyl phenyl, 3, 5-di-tert-butylphenyl, 3, 5-diphenylphenyl, (trifluoromethyl) phenyl, unsubstituted alkyl (e.g., unsubstituted C₁-C₅ alkyl) , unsubstituted carbazole, unsubstituted carbazole (e.g., substituted with one or more unsubstituted C₁-C₅ alkyl or substituted C₁-C₅ alkyl (such as tert-butyl) ) , unsubstituted 1, 3, 4-oxadiazole, substituted oxadiazole (e.g., 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, diphenylphosphine oxide, 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with an unsubstituted phenyl, tert-butyl phenyl, 3, 5-di-tert-butylphenyl, 3, 5-diphenylphenyl, (trifluoromethyl) phenyl, or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with an unsubstituted alkyl (e.g., unsubstituted C₁-C₅ alkyl) or a substituted alkyl (e.g., substituted C₁-C₅ alkyl) .

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with an unsubstituted carbazole, unsubstituted carbazole (e.g., substituted with one or more unsubstituted C₁-C₅ alkyl or substituted C₁-C₅ alkyl (such as tert-butyl) ) , or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with an unsubstituted 1, 3, 4-oxadiazole, substituted oxadiazole (e.g., 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with a substituted or unsubstituted diphenylphosphine oxide, preferably an unsubstituted diphenylphosphine.

In some forms, the compound is as described above for Formula I, except that ring A is preferably substituted with a 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole.

In some forms, the compound is as described above for Formula I, except that ring B and ring B’ are independently a substituted or unsubstituted phenyl, a substituted or unsubstituted naphthalyl, a substituted or unsubstituted carbazole, a substituted or unsubstituted fluorene, a substituted or unsubstituted thiophene, a substituted or unsubstituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring B and ring B’ are independently an unsubstituted phenyl, an unsubstituted naphthalyl, an unsubstituted carbazole, an unsubstituted fluorene, an unsubstituted thiophene, an unsubstituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, 6, 9-di-tert-butyl-7b-boraindeno [1, 2, 3-jk] fluorene, benzo [5, 6] [1, 4] oxazino [2, 3, 4-kl] phenoxazine, or a combination thereof.

In some forms, the compound is as described above for Formula I, except that ring B and ring B’ are independently a substituted phenyl, a substituted naphthalyl, a substituted carbazole, a substituted fluorene, a substituted thiophene, a substituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.

When ring B, ring B’ , or both contains substituted group, as described herein, ring B, ring B’ , or both are preferably substituted with a moiety independently selected from unsubstituted alkyl (e.g., C₁-C₅ unsubstituted alkyl) , substituted alkyl (e.g., C₁-C₅ substituted alkyl) , unsubstituted alkoxy (e.g., C₁-C₅ unsubstituted alkoxy) , substituted alkoxy (e.g., C₁-C₅ substituted alkoxy) , halogen, 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, or a combination thereof.

Specific examples of the luminescent tetradentate ligand-containing gold (III) compounds of formula (I) include the following:

In some embodiments of the subject matter described herein, the luminescent tetradentate ligand-containing gold (III) compounds of formula (I) are prepared. The compounds are represented throughout by their monomeric structure. As is well known to those skilled in the art, the compounds may also be present as dimers, trimers, oligomers or dendrimers.

The luminescent tetradentate ligand-containing gold (III) compounds can be used to form thin films by spin-coating, vacuum deposition or other known fabrication methods and can be applied in OLEDs. With reference now to FIG.1, the gold (III) compounds as in one or more embodiments herein can be fabricated into an OLED structure 100. The OLED structure 100 includes a cathode 110, an electron transport layer 120 ( “ETL” ) , a light-emitting layer 130 (or “emissive layer” ) , a hole-transporting layer 140 ( “HTL” ) , an anode 150, and a substrate 160. The light-emitting layer 130 includes a luminescent gold (III) compound as described herein. Although not shown in FIG. 1, in one or more embodiments, OLED 100 further includes a hole blocking layer and/or a carrier confinement layer to improve the device performance. Device structures with modifications to include various carrier blocking layers, carrier injection layers and interlayers can also be used to improve the device performance.

The cathode 110 and anode 150 are a pair of electrodes sandwiching these plurality of semiconductor layers that cause EL when voltage is applied to the OLED 100. The cathode 110 acts as a transmissive electron injector that injects electrons into the organic emissive layer 130 when the cathode is negatively biased. The cathode comprises a thin fluoride layer (which may be omitted) and a metal or metal alloy, preferably having a work function of less than 4 eV. The cathode 110 may be made of suitable materials such as, for example, Mg: Ag, Ca, Li: Al, Al, or Ba. The anode 150 injects holes into the emissive layer when the anode is positively biased. The anode 150 is composed of a conductive and optionally transmissive layer. In one or more embodiments, viewing the emissive layer 130 through the substrate 160 is desirable, and the anode is transparent. In other embodiments, the emissive layer 130 is viewed through the top electrode and the transmissive characteristics of anode 150 are immaterial, and therefore any appropriate materials including metals or metal compounds having a work function of greater than 4.1 eV may be used. For example, appropriate metals include silver, gold, iridium, nickel, molybdenum, palladium, and platinum. In one or more embodiments, the anode 150 is transmissive, and suitable materials are metal oxides, including indium-tin oxide, aluminum-or indium-doped zinc oxide, tin oxide, magnesium-indium oxide, nickel-tungsten oxide, and cadmium-tin oxide. The preferred metals and metal oxides can be deposited by evaporation, sputtering, laser ablation, and chemical vapor deposition. The cathode 110 and anode 150 can have thicknesses between 100-200 nm.

In one or more embodiments, the anode 150 layer is positioned on top of a substrate 160. The substrate 160 is electrically insulated and is used to emit the light created by the OLED 100, in which it is typically made of transparent material. For example, the substrate 160 can be made of glass, plastic foil, flexible substrate or a transparent polymer. In one or more alternative embodiments, the substrate is opaque and comprises one or more semiconducting materials or ceramics. In one embodiment of the subject matter described herein, the emissive layer 130 is viewed through the substrate 160, or through both sides of the device, and substrate comprises a transparent glass substrate or a plastic foil. In other embodiments, the emissive layer 130 is viewed only through the top electrode, and substrate 160 comprises an opaque semiconductor or ceramic wafers.

The ETL 120 provides high electron affinity and high electron mobility to the OLED 100 for electrons to flow across the various OLED layers. To do this, the electron-transporting layer 120 includes materials or mixtures of materials having a high ionization potential and wide optical band gap. In one or more embodiments, the ETL 120 has a thickness between 30-80 nm. In one or more embodiments, additional electron transporting materials are added to ETL 120 to facilitate electron injection. The materials for the ETL 120 are selected to maximize OLED efficiency. As some non-limiting examples, suitable electron-transporting materials include but are not limited to 1, 3, 5-tris (phenyl-2-benzimidazolyl) -benzene (TPBI) , 1, 3, 5-tri [ (3-pyridyl) -phen-3-yl] benzene (TmPyPB) , bathocuproine (BCP) , bathophenanthroline (BPhen) and bis (2-methyl-8-quinolinolate) -4- (phenylphenolate) aluminum (BAlq) , tris- [2, 4, 6-trimethyl-3- (pyridin-3-yl) phenyl] borane (3TPYMB) , and 1, 3-bis [3, 5-di (pyridin-3-yl) phenyl] benzene (BmPyPhB) . In one embodiment, the electron-transporting layer 120 is prepared as an organic film by thermal evaporation, spin-coating, ink-jet printing from a solution, or other known fabrication methods. Light-emitting layer or emissive layer 130 in FIG. 1 is formed by doping the phosphorescent gold (III) metal complex as a dopant into a host material. Suitable host materials should be selected so that the triplet excitons can be transferred efficiently from the host material to the phosphorescent dopant material. Suitable host materials include, but are not limited to, certain aryl amines, triazoles and carbazole compounds. Examples of desirable hosts include, but are not limited to, CBP, MCP, TCTA, 3- (4-biphenylyl) -4-phenyl-5-tert-butylphenyl-1, 2, butylphenyl-1, 2, 4-triazole (TAZ) , UGH2, and PVK. In certain embodiments, any one of the compounds 1 to 416 can be doped into a mixed host consisting of non-limiting examples of CBP, MCP, TCTA, TAZ, UGH2, PVK or a combination thereof.

In general, the emissive layer 130 is sandwiched between the hole-transporting layer 140 and the electron-transporting layer 120. To ensure an efficient exothermic energy transfer between the host material and the dopant material, the triplet energy of the host material must be larger than that of the dopant material. In addition, both the ionization potential and the electron affinity of the host material should be larger than those of the dopant material in order to achieve efficientenergy transfer from the host to the dopant. In order to confine triplet excitons within the emissive layer, the triplet energy of the hole-transporting material and electron-transporting material should be larger than that of the dopant material.

The HTL 140 is layered on top of the anode 150 and plays a role in the adjustment of electron/hole injection to attain transport balance of charge carriers in the emissive layer 130 of the OLED 100. In one or more embodiments, the HTL 140 has a thickness between 30-80 nm. The materials for the HTL 140 are selected to maximize OLED efficiency. As some non-limiting examples, the HTL 140 can include, but is not limited to, polycyclic aromatic compounds, for example, 4, 4’ -bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB) , 4, 4’ -bis [N- (3-methylphenyl) -N-phenylamino] biphenyl (TPD) , 4, 4’ , 4” -tris [ (3-methylphenyl) phenylamino] triphenylamine (MTDATA) , and di- [4- (N, N-ditolyl-amino) phenyl] cyclohexane (TAPC) . In addition, polymeric hole-transporting materials can be used, including PVK, polythiophene, polypyrrole, polyaniline, and copolymers including poly (3, 4-ethylenedioxythiophene) : poly (styrene-sulfonate) (PEDOT: PSS) .

In some embodiments of the subject matter described herein, luminescent gold (III) compounds are either the primary luminescent material or a secondary luminescent material in the device, as shown FIG. 1. In some embodiments of the subject matter described herein, the tetradentate ligand-containing gold (III) compounds are employed as electrophosphorescent dopants in multilayer OLED. Advantageously, the tetradentate ligand-containing gold (III) compounds can be deposited in the OLEDs by spin-coating, screen printing, ink-jet printing and vacuum deposition. The high solubility of the luminescent tetradentate ligand-containing gold (III) compounds in a variety of organic solvents permits simple and economic manufacturing and patterning of large-area displays.

In some embodiments of the subject matter described herein, the luminescent tetradentate ligand-containing gold (III) compounds of formula (I) are prepared in high purity. The synthetic method involves providing the luminescent tetradentate ligand-containing gold (III) compounds of formula (I) from the cyclometalated gold (III) precursor compounds or their equivalents. The gold (III) precursor compounds can be prepared by any methods known to those skilled in the art, for example, but are not limited to, the methods disclosed inF. Synthesis 1 (1976) ; Wong, K.H.; Cheung, K.K.; Chan, M.C.; Che, C.M. Organometallics, 17, 5305 (1998) ; Yam, V W.-W.; Wong, K.M.-C.; Hung, L.-L.; Zhu, N. Angew. Chem. Int. Ed. 4, 3107 (205) ; Au, V.K.-M.; Wong, K.M.-C.; Zhu, N.; Yam, V W.-W. Chem. Eur. J. 17, 130 (2011) ; Roca, D.-A.; Smith, D.A.; Bochmann, M. Chem. Commun. 48, 7247 (2012) ; David, B.; Monkowius, U.; Rust, J.; Lehmann, C.W.; Hyzak, L.; Mohr, F. Dalton Trans. 43, 11059 (2014) ; Maity, A.; Sulicz, A.N.; Deligonul, N.; Zeler, M.; Hunter, A. D.; Gray, T. G. Chem. Sci. 6, 981 (2015) ; Kumar, R.; Linden, A.; Nevado, C. Angew. Chem. Int. Ed. 54, 14287 (2015) ; Zhou, D.; To, W.-P.; Tong, G.S.M.; Cheng, G.; Du, L.; Phillips, D.L.; Che, C.-M. Angew. Chem. Int. Ed. 59, 6375 (2017) ; Lee, C.-H.; Tang, M.-C.; Kong, F.K.-W.; Cheung, W.-L.; Ng, M., Chan, M.-Y.; Yam, V.W.-W.J. Am. Chem. Soc. 142, 1, 520 (2020) .

In some embodiments, the tetradentate ligand-containing gold (III) compounds can be further modified by incorporation of the substituents to the tetradentate ligand-containing gold (III) compounds.

In some forms, purification can be carried out by any method or combination of methods, including chromatography, extraction, crystallization, sublimation or any combination thereof.

In one or more embodiments, the luminescent gold (III) compounds disclosed herein are deposited as a thin layer on a substrate layer. In one or more embodiments, the thickness of the deposited gold (III) compound is 10-20 nm, 21-30 nm, 31-40 nm, 41-50 nm, 51-60 nm, 61-70 nm, 71-80 nm, 81-90 nm, or 91-100 nm.

The present subject matter described herein will be illustrated more specifically by the following non-limiting examples, it being understood that changes and variations can be made therein without deviating from the scope and the spirit of the disclosure as hereinafter claimed. It is also understood that various theories as to why the disclosure works are not intended to be limiting.

Examples

EXAMPLE 1

Compounds 1-5 were prepared according to the following methodology as illustrated in Scheme 1. All the tetradentate ligand-containing gold (III) compounds were synthesized by the reaction of cyclometalated gold (III) precursor compounds or their equivalents with the corresponding heterocycles in the presence of a catalytic amount of palladium catalyst in base and organic solvent in one pot. For example, compound 1 was synthesized by stirring a mixture of [Au {^tBuC^ (^tBuC₆H₅) N^CMe-2-Br-5} Cl] (500 mg, 0.65 mmol) with 3, 6-di-tert-butyl-1- (4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) -9H-carbazole (275 mg, 0.65 mmol) , palladium catalyst and base in degassed solvent at reflux temperature overnight (Scheme 1) . The reaction mixture was then extracted with dichloromethane and was washed with deionized water. The organic layer was dried over anhydrous magnesium sulfate, filtered and evaporated to dryness under reduced pressure. The crude product was then purified by flash column chromatography on silica gel using hexane-dichloromethane as eluent. Subsequent recrystallization by diffusing pentane or methyl tert-butyl ether into the concentrated chloroform solution of the compound gave the resulting complex as orange-red crystals. ¹H and ¹³C {¹H} NMR spectra were recorded on Bruker AVANCE 500 or 600 (500 MHz and 600 MHz for ¹H respectively; 125 MHz and 150 MHz for ¹³C respectively) Fourier-transform NMR spectrometer with chemical shifts reported relative to the tetramethylsilane (δ 0 ppm) . The results of the analyses confirm the high purity of all the compounds.

Scheme 1

wherein:

The characteristic spectroscopic properties of compounds 1-5 are as follows:

Compound 1: Yield: 70 mg, 14 %. ¹H NMR (500 MHz, CDCl₃, 298 K, relative to Me₄Si, δ/ppm) : δ1.23 (s, 9H) , 1.35 (s, 9H) , 1.49 (s, 9H) , 1.58 (s, 9H) , 2.45 (s, 3H,) , 7.07 (s, 1H) , 7.10 (d, J = 10 Hz, 1H) , 7.22-7.27 (m, 7H) , 7.42 (s, 1H) , 7.70 (d,J = 10 Hz, 1H) , 7.91 (s, 1H) , 8.04 (s, 1H) , 8.10 (s, 1H) , 8.17-8.19 (m, 2H) . ¹³C {¹H} NMR (150 MHz, CDCl₃, δ/ppm) : δ 23.33, 31.06, 31.22, 32.07, 32.38, 34.56, 34.76, 35.35, 113.53, 114.99, 115.69, 118.04, 118.14, 118.25, 121.89, 122.90, 124.44, 124.64, 124.94, 125.58, 125.94, 126.14, 126.81, 131.46, 132.43, 134.38, 134.86, 135.57, 137.36, 139.96, 141.05, 144.29, 146.13, 147.05, 153.07, 153.39, 153.60, 163.83, 164.01, 164.08, 169.79. HRMS (positive ESI) calcd for C₅₂H₅₅AuN₂: m/z= 904.4025 [M] ⁺; found m/z= 904.4039 [M] ⁺. Elemental analyses: Found (%) : C 69.94, H 6.21, N 3.01. Calcd for C₅₂H₅₅AuN₂: C 69.01, H 6.13, N 3.10.

Compound 2: Yield: 200 mg, 40 %. ¹H NMR (500 MHz, CDCl₃, 298 K, relative to Me₄Si, δ/ppm) : δ1.27 (s, 9H) , 1.42 (s, 9H) , 1.51 (s, 9H) , 1.60 (s, 9H) , 4.00 (s, 3H) , 7.07 (s, 1H) , 7.32 (s, 1H) , 7.37 (d, J = 10 Hz, 1H) , 7.56 (d, J = 10 Hz, 2H) , 7.61 (s, 2H) , 7.67 (d, J = 10 Hz, 2H) , 7.88 (d, J = 10 Hz) , 8.16 (s, 1H) , 8.18 (s, 3H) , 8.48 (d, J = 10 Hz, 2H) . ¹³C {¹H} NMR (150 MHz, CDCl₃, δ/ppm) : δ 31.07, 31.26, 32.07, 32.39, 34.61, 34.80, 34.82, 35.38, 55.61, 111.27, 113.40, 115.03, 115.07, 117.79, 117.89, 119.60, 121.81, 123.05, 124.27, 124.71, 125.54, 126.01, 126.27, 126.57, 126.60, 126.93, 134.30, 134.73, 135.16, 137.29, 140.11, 141.24, 144.52, 147.42, 153.28, 153.28, 153.61, 157.19, 163.05, 163.58, 163.92, 169.25. HRMS (positive ESI) calcd for C₅₂H₅₅AuN₂O: m/z= 920.3975 [M] ⁺; found m/z= 920.3984 [M] ⁺. Elemental analyses: Found (%) : C 67.75, H 6.21, N 3.01. Calcd for C₅₂H₅₅AuN₂O: C 67.81, H 6.02, N 3.04.

Compound 3: Yield: 240 mg, 48 %. ¹H NMR (500 MHz, CDCl₃, 298 K, relative to Me₄Si, δ/ppm) : δ 1.28 (s, 9H) , 1.41 (s, 9H) , 3.78 (s, 3H) , 6.86 (d, J = 10 Hz, 1H) , 7.21 (t, J = 5 Hz, 1H) , 7.26-7.27 (m, 1H) , 7.30 (d, J = 10 Hz, 2H) , 7.42-7.44 (m, 3H) , 7.46 (d, J = 10 Hz, 2H) , 7.51 (d, J = 10 Hz, 1H) 7.98 (d, J = 10 Hz, 1H) , 8.04 (d, J = 10 Hz, 1H) , 8.12-8.15 (m, 3H) , 8.28-8.30 (m, 2H) . ¹³C {¹H} NMR (150 MHz, CDCl₃, δ/ppm) : δ 14.13, 29.72, 31.18, 31.26, 31.60, 34.83, 35.39, 54.43, 55.46, 111.42, 113.38, 117.63, 118.42, 118.57, 118.66, 123.19, 123.66, 124.76, 125.16, 125.74, 125.98, 126.06, 126.72, 126.75, 126.89, 134.21, 134.55, 135.29, 138.35, 146.10, 147.40, 153.37, 153.63, 153.72, 157.24, 163.02, 163.63, 169.38. HRMS (positive ESI) calcd for C₄₄H₃₉AuN₂O: m/z= 808.2723 [M]⁺; found m/z= 808.2741 [M] ⁺. Elemental analyses: Found (%) : C 65.45, H 4.91, N 3.30. Calcd for C₄₄H₃₉AuN₂O: C 65.34, H 4.86, N 3.46.

Compound 4: Yield: 330 mg, 66 %. ¹H NMR (500 MHz, CDCl₃, 298 K, relative to Me₄Si, δ/ppm) : δ1.08 (s, 9H) , 1.44 (s, 9H) , 1.45 (s, 3H) , 2.03 (s, 3H) , 4.09 (s, 3H,) , 6.87 (s, 1H) , 6.93-7.02 (m, 3H) , 7.08 (d, J = 10 Hz, 1H) , 7.17-7.21 (m, 2H) , 7.41 (t, J = 5 Hz, 2H) , 7.63, (d, J = 10 Hz, 3H) , 7.07 (s, 1H) , 7.76 (d, J = 10 Hz, 2H) , 7.87 (d, J = 10 Hz, 1H) , 8.33 (d, J = 10 Hz, 1H) , 8.48 (s, 1H) . ¹³C {¹H} NMR (150 MHz, CDCl₃, δ/ppm) : δ 23.53, 27.25, 30.88, 31.28, 34.82, 34.88, 37.40, 55.83, 111.49, 113.64, 119.04, 119.46, 121.36, 121.48, 122.10, 122.77, 124.16, 124.58, 125.12, 126.28, 127.19, 127.65, 128.19, 128.43, 128.83, 133.15, 133.45, 135.26, 137.60, 138.68, 140.90, 146.60, 147.95, 153.59, 153.89, 153.91, 157.08, 162.94, 164.16, 167.33, 172.96. HRMS (positive ESI) calcd for C₄₇H₄₅AuN₂O: m/z= 850.3192 [M] ⁺; found m/z= 850.4305 [M] ⁺. Elemental analyses: Found (%) : C 66.40, H 5.23, N 3.12. Calcd for C₄₇H₄₅AuN₂O: C 66.35, H 5.33, N 3.29.

Compound 5: Yield: 370 mg, 74 %. ¹H NMR (500 MHz, CDCl₃, 298 K, relative to Me₄Si, δ/ppm) : δ1.08 (s, 9H) , 1.42 (s, 9H) , 3.92 (s, 3H) , 6.62-6.65 (m, 2H) , 6.68-6.83 (m, 4H) , 6.91 (d, J = 10 Hz, 1H) , 7.05 (s, 1H) , 7.18 (d, J = 10 Hz, 1H) , 7.41-7.47 (m, 3H) , 7.57 (d, J = 8 Hz, 2H) , 7.65 (d, J = 8 Hz, 2H) , 8.07 (d, J = 10 Hz, 1H) , 8.28 (s, 1H) . ¹³C {¹H} NMR (150 MHz, CDCl₃, δ/ppm) : δ30.93, 31.29, 34.86, 55.69, 111.46, 113.57, 119.52, 123, 01, 124.32, 126.20, 127.14, 127.91, 132.99, 133.04 134.88, 146.47, 153.52, 153.77, 153.81, 157.20, 162.57, 163.77, 172.19. HRMS (positive ESI) calcd for C₄₄H₃₉AuN₂O₂: m/z= 824.2672 [M]⁺; found m/z= 824.2683 [M] ⁺. Elemental analyses: Found (%) : C 64.26, H 4.84, N 3.35. Calcd for C₄₄H₃₉AuN₂O₂: C 64.08, H 4.77, N 3.40.

EXAMPLE 2

UV-Vis Absorption Properties

The electronic absorption spectra of the tetradentate gold (III) compounds 1-5 in dichloromethane solution at 298 K showed intense absorption bands at ca. 240-309 nm with extinction coefficients in the order of 10⁴ dm³mol^-1cm^-1, and a moderately intense vibronic-structured absorption bands at ca. 360-418 nm with the lowest-energy absorption bands at ca. 484-559 nm, as listed in TABLE 1 and FIG. 2.

TABLE 1

Photophysical data for compounds 1-5

EXAMPLE 3

Emission Properties and Thermal Stabilities

Upon photo-excitation in dichloromethane solution at room temperature, compounds 1-4 display Gaussian-shaped emission bands with maxima at ca. 645-748 nm as shown in FIG. 3 and their respectable PLQYs at room temperature are summarized in TABLE 1. FIG. 4 show the normalized emission spectra of compounds 1-4 doped in 5 wt%MCP thin films at 298 K. All the emission spectra of the doped thin films are in Gaussian shape. The emission bands of compound 1-4 doped in 5 to 20 wt%MCP at 298 K are found to be red-shifted with increasing dopant concentration (FIG. 5 and TABLE 2) . These compounds also display red-shifted emission bands with increasing electron-donating ability of the donor unit, where the trend is consistent with the emission in the solution-state.

TABLE 2

Photophysical data for compound 1-4 doped in MCP thin film at 298 K

^[a] Φ_film of gold (III) compound excited at wavelength of 320 nm.

EXAMPLE 4

A solution-processed OLED according to an embodiment of the disclosure was constructed in the following manner:

a) A transparent anode ITO-coated borosilicate glass substrate (38 mm × 38 mm) with sheet resistance of 30 Ω per square was ultrasonicated in the commercial detergent Decon 90, rinsed in deionized water having a resistivity of 18.2 Mega-ohm for 15 minutes, and then dried in an oven at 120 degree C for an hour. The substrate was next subjected to an UV-ozone treatment in a Jelight 42-220 UVO-Cleaner equipped with a mercury grid lamp for 15 minutes in order to increase the work function of the ITO-coated glass substrate for better hole injection into the organic layer.

b) A 40-nm thick PEDOT: PSS hole-transporting layer was spin-coated by using a Laurell WS-400Ez-6NPP-Lit2 single wafer spin processor at 7000 rpm for 30 seconds onto the ITO-coated glass substrate of step (a) and baked at 110 degree C for 10 minutes in air.

c) A 30-nm thick light-emitting layer was spin-coated by using a Laurell WS-400Ez-6NPP-Lit2 single wafer spin processor at 6000 rpm for 25 seconds onto PEDOT: PSS layer of step (b) , and baked at 80 degree C for 10 minutes in air, in which compound 1 was doped into light-emitting MCP layer at different concentrations in the range from 5 to 20 wt%;

d) The substrate was put into a vacuum chamber, and the chamber was pumped down from 1 bar to 5×10^-6 mbar;

e) A 5-nm thick 3TPYMB hole blocking layer was deposited by thermal evaporation on doped MCP light-emitting layer of step (c) .

f) A 30-nm TmPyPB electron-transporting layer was deposited by thermal evaporation on the 3TPYMB layer of step (e) .

g) A 0.8-nm thick LiF layer and a 80 nm thick Al layer were deposited by thermal evaporation on the TmPyPB layer of step (f) to form an electron-injecting cathode.

3TPYMB, TmPyPB, LiF and Al were prepared by thermal evaporation from tantalum boats by applying current through the tantalum boats. Deposition rates were monitored with a quartz oscillation crystal and a Sigma SQM-242 quartz crystal card and controlled at 0.1-0.2 nm s^-1 for both organic and metal layers. Current density-voltage-luminance characteristics of organic EL devices were measured with a programmable Keithley model 2400 power source and a Spectrascan PR-655 colorimeter under ambient air conditions.

As depicted in FIG. 6, the EL spectra for all the devices are almost identical to their emission spectra in solution and solid-state thin films without any undesirable emission coming from the adjacent carrier-transporting layers or the host materials. With increasing the dopant concentration, the peak maximum has been slightly red-shifted from 608 nm to 616 nm, which is arising from the excimeric emission arising from the π-π stacking of the cyclometalating tetradentate ligand, in good agreement with the emission spectra of1 in solid-state thin films. In addition, the optimized device doped with 20 wt%compound 1 demonstrates a high EQE of 5.6 %, as shown in FIG. 7.

EXAMPLE 5

The same materials and processing procedures were employed as described in Example 4 except that compound2 was doped into MCP as light emissive layer. All the devices show a structureless red emission band with band maximum at around 609 nm (FIG. 8) . The optimized device doped with 20 wt%compound 2 exhibits high EQE of 8.1 % (FIG. 9) .

EXAMPLE 6

The same materials and processing procedures were employed as described in Example 4 except that compound3 was doped into MCP as light emissive layer. All the devices show a structureless red emission band with band maximum at around 578 nm to 593 nm (FIG. 10) . The optimized device doped with 20 wt%compound 3 exhibits high EQE of 9.2 % (FIG. 11) .

EXAMPLE 7

A vacuum-deposited OLED according to an embodiment of the disclosure was constructed in the following manner:

b) The substrate was put into a vacuum chamber, and the chamber was pumped down from 1 bar to 5×10^-6 mbar;

c) A 40-nm thickN, N’ -bis (naphthalen-1-yl) -N, N’ -bis (phenyl) -2, 2’ -dimethylbenzidine (α-NPD) hole-transporting layer was deposited by thermal evaporation onto the ITO-coated glass substrate of step (a) ;

d) A 5-nm thick TCTA carrier confinement layer was deposited by thermal evaporation onto the α-NPD of step (c) ;

e) A 20-nm thick light-emitting layer was deposited by thermal evaporation onto the TCTA layer of step (d) , in which 2, 5, 8, 11, and 14 %v/v compound 1 was doped into light-emitting 3, 3’ -di (9H-carbazol-9-yl) biphenyl (mCBP) layer;

f) A 50-nm thick 1, 3, 5-tris (6- (3- (pyridin-3-yl) phenyl) pyridine-2-yl) benzene (Tm3PyP26PyB) electron-transporting layer was deposited by thermal evaporation on doped mCBP light-emitting layer of step (e) .

g) A 1-nm thick LiF layer and a 150-nm thick Al layer were deposited by thermal evaporation on the Tm3PyP26PyB layer of step (f) to form an electron-injecting cathode.

All materials were prepared by thermal evaporation from tantalum boats by applying current through the tantalum boats. Deposition rates were monitored with a quartz oscillation crystal and a Sigma SQM-242 quartz crystal card and controlled at 0.1-0.2 nm s^-1 for both organic and metal layers. Current density-voltage-luminance characteristics of organic EL devices were measured with a programmable Keithley model 2400 power source and a Spectrascan PR-655 colorimeter under ambient air conditions.

All the devices show structureless red emission bands with band maxima from 604 nm to 628 nm (FIG. 12) . FIG. 13 depicts the EQEs of the vacuum-deposited devices based on compound 1. Notably, high EQE of 13.4 %has been realized for the optimized device doped with 5 %v/v compound 1.

EXAMPLE 8

The same materials and processing procedures were employed as described in Example 7 except that compound2 was doped into mCBP as light emissive layer. All the devices show structureless red emission bands with band maxima from 600 nm to 620 nm (FIG. 14) . The optimized device doped with 11 %v/v compound 2 exhibits high EQE of 13.1 % (FIG. 15) .

EXAMPLE 9

The same materials and processing procedures were employed as described in Example 7 except that compound 3 was doped into mCBP as light emissive layer. All the devices show structureless orange emission bands with band maxima from 572 nm to 600 nm (FIG. 16) . The optimized device doped with 5 %v/v compound 3 exhibits high EQE of 11.6 % (FIG. 17) .

EXAMPLE 10

The same materials and processing procedures were employed as described in Example 8 except that compound 4 was doped into mCBP as light emissive layer. All the devices show structureless red emission bands with band maxima from 648 nm to 668 nm (FIG. 18) . The optimized device doped with 11 %v/v compound 4 exhibits high EQE of 2.1 % (FIG. 19) .

EXAMPLE 11

OLED Lifetime Measurement

c) A 10-nm thick dipyrazino [2, 3-f: 2’ , 3’ -h] quinoxaline-2, 3, 6, 7, 10, 11-hexacarbonitrile (HATCN) hole-injection layer was deposited by thermal evaporation onto the ITO-coated glass substrate of step (a) ;

d) A 40-nm thick α-NPD hole-transporting layer was deposited by thermal evaporation onto the HATCN of step (c) ;

e) A 10-nm thick 9, 9’ , 9” -triphenyl-9H, 9’ H, 9” H-3, 3’ : 6’ , 3” -tercarbazole (TrisPCz) carrier confinement layer was deposited by thermal evaporation onto the α-NPD of step (d) ;

f) A 40-nm thick light-emitting layer was deposited by thermal evaporation onto the TrisPCz layer of step (e) , in which 11 %v/v compound 1 was doped into light-emitting 2, 6-di (9H-carbazol-9-yl) pyridine (PYD-2Cz) layer;

g) A 10-nm thick 2, 4, 6-tris [3- (diphenylphosphinyl) phenyl] -1, 3, 5-triazine (T2T) hole-blocking layer was deposited by thermal evaporation onto the doped PYD-2Cz layer of step (f) ;

h) A 40-nm thick 2, 7-di (2, 2’ -bipyridin-5-yl) triphenylene (BPyTP2) electron-transporting layer was deposited by thermal evaporation on T2T layer of step (g) ;

i) A 1-nm thick LiF layer and a 150-nm thick Al layer were deposited by thermal evaporation on the BPyTP2 layer of step (h) to form an electron-injecting cathode.

All materials were prepared by thermal evaporation from tantalum boats by applying current through the tantalum boats. Deposition rates were monitored with a quartz oscillation crystal and a Sigma SQM-242 quartz crystal card and controlled at 0.1-0.2 nm s^-1 for both organic and metal layers. Devices were encapsulated in a glovebox under nitrogen. The operational lifetime of the vacuum-deposited device was measured by McScience OLED Lifetime Measurement System by accelerated lifetime testing under a constant driving current density of 10 mA cm^-2 under ambient conditions.

EXAMPLE 12

The same materials and processing procedures were employed as described in Example 11 except that compound 2 was doped into PYD-2Cz as light emissive layer.

EXAMPLE 13

The same materials and processing procedures were employed as described in Example 11 except that compound 3 was doped into PYD-2Cz as light emissive layer.

FIG. 20 depicts the relative luminance of devices based on 1-3 as a function of time. Apparently, device based on compound 1 demonstrates a longer operational lifetime. Particularly, the estimated lifetime at LT₇₀ (i.e. the time required for the luminance to drop to 70 %of its initial value) of device based on compound 1 is ～73, 670 hours and those for device based on compounds 2 and 3 are ～2, 490 hours and ～5, 480 hours, respectively. In addition, the estimated half-lifetime (LT₅₀, the time required for the luminance to drop to 50 %of its initial value) of device based on 1 is ～188, 710 hours.

EXAMPLE 14

TABLES 3 and 4 show the key data of vacuum-deposited OLEDs based on compounds 1-3 measured at 1000 cd m^-2 and 100 cd m^-2.

TABLE 3

TABLE 4

^[a] CE represents current efficiency.

^[b] PE represents power efficiency.

^[c] EQE represents external quantum efficiency.

^[d] CIE coordinates are taken at a luminance of 100 cd m^-2.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

A luminescent gold (III) compound having the chemical structure shown in the generic formula (I) ,

wherein:

(a) ring A is coordinated to the Au atom through a nitrogen atom, and comprises a substituted or unsubstituted pyridyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted thienopyridinyl, a substituted or unsubstituted furopyridinyl group, a substituted or unsubstituted selenophenopyridinyl group;

(b) rings B and B’ are each coordinated to the Au atom through a carbon atom, and are each independently a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;

(c) each D is independently at each occurrence absent or a cyclic or acyclic moiety wherein: (ci) the cyclic moiety is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted polycyclic group, a substituted or unsubstituted acene, and a substituted or unsubstituted a heteroacene; and (cii) the acyclic moiety is selected from the group consisting of a substituted or unsubstituted alkynyl, a substituted or unsubstituted arylalkynyl, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted alkoxy, and a substituted or unsubstituted arylalkoxy;

(d) the dashed curved line in ring E is absent or present, wherein if the dashed curved line in ring E is absent, there is no bond connection between the ring structures D; if the dashed curved line in ring E is present, ring E is a substituted or unsubstitutedN-containing ring with ring size of 5-10 that may contain either one or more chemical moieties selected from -C (RR′) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′) -, -Se-, -As (R) , -CH=CH-and -CR=CR′-, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, thioether, selenoether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(e) the dashed linear lines independently represent the absence or presence of a bond; B, B’, and each D, independently represent a substituted or unsubstituted monocyclic aryl, a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) , or a substituted or unsubstituted heteroaryl group; or D, Y, and B together and/or D, Y, and B’ together, independently form a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) ; X and Y are each independently at each occurrence absent or non-coordination sites selected from the group consisting of -C (RR′) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′) -, -Se-, -As (R) , -CH=CH-and -CR=CR′-, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonateester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(f) whereinp and q are each independently 0, 1, 2 or 3; andp and q are not both equal to 0; wherein (fi) whenp or q is equal to 0, there is no bond connection between the ring structures B and D, or B′ and D; (fii) when Y is absent andp or q is equal to 1, there is a single bond linked between the ring structures B and D, or B′ and D, respectively; (fiii) when Y is present andp or q is equal to 1, there is a single bond linked between Y and the ring structures B and D, or B′ and D;

(g) wherein r and s are each independently 1, 2 or 3; wherein (gi) when X is absent ands or r is equal to 1, there is a single bond linked between the ring structures A and B′, or A and B; (gii) when X is present and s or r is equal to 1, there is a single bond between X and the ring structures A and B′, or A and B;

(h) Z and Z’ are each a substituent on Ring B and B′, respectively, and are each independently selected from the group consisting of substituted or unsubstituted alkyl (e.g., substituted or unsubstituted C₁-C₁₀ alkyl) , substituted or unsubstituted haloalkyl (e.g., substituted or unsubstituted C₁-C₁₀ haloalkyl) , substituted or unsubstituted amine, substituted or unsubstituted alkoxy (e.g., substituted or unsubstituted C₁-C₁₀ alkoxy) , substituted or unsubstituted haloalkoxy (e.g., substituted or unsubstituted C₁-C₁₀ haloalkoxy) , substituted or unsubstituted alkylthio (e.g., substituted or unsubstituted C₁-C₁₀ alkylthio) , substituted or unsubstituted alkylselenyl (e.g., substituted or unsubstituted C₁-C₁₀ alkylselenyl) , hydroxyl, thiol, nitrile, nitro, F, Cl, Br, and I, and g and g’ are independently an integer between 1 and 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; wherein wheng or g’ is equal to 0, the substituent Z or Z’, respectively, is absent;

(i) n is zero, a positive integer or a negative integer.
The gold (III) compound according to claim 1, wherein ring A comprises a substituted pyridyl group, a substituted isoquinolinyl group, a substituted quinolinyl group, a substituted group, a substituted pyrimidinyl group, a substituted triazinyl group, a substituted carbolinyl group, a substituted thienopyridinyl, a substituted furopyridinyl group, or a substituted selenophenopyridinyl group.
The gold (III) compound according to claim 1 or 2, wherein ring A comprises a substituted group selected from an unsubstituted phenyl, tert-butyl phenyl, 3, 5-di-tert-butylphenyl, 3, 5-diphenylphenyl, (trifluoromethyl) phenyl, unsubstituted alkyl (e.g., unsubstituted C₁-C₅ alkyl) , unsubstituted carbazole, unsubstituted carbazole (e.g., substituted with one or more unsubstituted C₁-C₅ alkyl or substituted C₁-C₅ alkyl (such as tert-butyl) ) , unsubstituted 1, 3, 4-oxadiazole, substituted oxadiazole (e.g., 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, diphenylphosphine oxide, 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.
The gold (III) compound according to any one of claims 1 to 3, wherein ring A comprises a substituted group selected independently selected from:

(i) an unsubstituted phenyl, tert-butyl phenyl, 3, 5-di-tert-butylphenyl, (trifluoromethyl) phenyl, 3, 5-diphenylphenyl, or a combination thereof,

(ii) an unsubstituted alkyl (e.g., unsubstituted C₁-C₅ alkyl) or substituted alkyl (e.g., substituted C₁-C₅ alkyl) ,

(iii) an unsubstituted carbazole, unsubstituted carbazole (e.g., substituted with one or more unsubstituted C₁-C₅ alkyl or substituted C₁-C₅alkyl (such as tert-butyl) ) , or a combination thereof,

(iv) an unsubstituted 1, 3, 4-oxadiazole, substituted oxadiazole (e.g., 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, or a combination thereof,

(v) a with a substituted or unsubstituted diphenylphosphine oxide, or

(vi) a 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole.
The gold (III) compound according to claim 1, wherein ring A is selected from an unsubstituted pyridyl group, an unsubstituted isoquinolinyl group, an unsubstituted quinolinyl group, an unsubstituted pyrazinyl group, an unsubstituted pyrimidinyl group, an unsubstituted triazinyl group, an unsubstituted carbolinyl group, an unsubstituted thienopyridinyl, an unsubstituted furopyridinyl group, or an unsubstituted selenophenopyridinyl group.
The gold (III) compound according to any one of claims 1 to 5, wherein ring B and ring B’ are independently a substituted or unsubstituted phenyl, a substituted or unsubstituted naphthalyl, a substituted or unsubstituted carbazole, a substituted or unsubstituted fluorene, a substituted or unsubstituted thiophene, a substituted or unsubstituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.
The gold (III) compound according to any one of claims 1 to 6, wherein ring B and ring B’ are independently a substituted phenyl, a substituted naphthalyl, a substituted carbazole, a substituted fluorene, a substituted thiophene, a substituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, or a combination thereof.
The gold (III) compound according to any one of claims 1 to 6, wherein ring B and ring B’ are independently substituted with a moiety independently selected from unsubstituted alkyl (e.g., C₁-C₅ unsubstituted alkyl) , substituted alkyl (e.g., C₁-C₅ substituted alkyl) , unsubstituted alkoxy (e.g., C₁-C₅ unsubstituted alkoxy) , substituted alkoxy (e.g., C₁-C₅ substituted alkoxy) , halogen, 2- (4- (tert-butyl) phenyl) -1, 3, 4-oxadiazole, or a combination thereof.
The gold (III) compound according to any one of claims 1 to 6, wherein ring B and ring B’ are independently an unsubstituted phenyl, an unsubstituted naphthalyl, an unsubstituted carbazole, an unsubstituted fluorene, an unsubstituted thiophene, an unsubstituted 6, 10-di-tert-butylindolo [3, 2, 1-jk] carbazole, 6, 9-di-tert-butyl-7b-boraindeno [1, 2, 3-jk] fluorene, benzo [5, 6] [1, 4] oxazino [2, 3, 4-kl] phenoxazine, or a combination thereof.
The gold (III) compound according to any one of claims 1 to 9, wherein the compound is deposited as a thin layer on a substrate layer.
The gold (III) compound according to claim 10, wherein the thin layer is prepared by vacuum deposition, spin-coating, or inkjet printing.
The gold (III) compound according to any one of claims 1 to 9, wherein the compound has photoluminescence properties within a range of about 380 to 1500 nm.
The gold (III) compound according to any one of claims 1 to 9, wherein the compound emits light in response to the passage of an electric current or to a strong electric field.
The gold (III) compound according to any one of claims 1 to 9, wherein the compound is used to fabricate an OLED.
The gold (III) compound according to claim 14, wherein the gold (III) compound serves as the light-emitting layer of the OLED.
The gold (III) compound according to claim 15, wherein the gold (III) compound serves as a dopant in the light-emitting layer or emissive layer of the OLED.
A gold (III) compound having one of the following structures:
A method for preparing a luminescent compound with cyclometalated tetradentate ligand comprising the steps of:

wherein:

(a) R¹, R², R³, R⁴ and R⁵ groups are each independently selected from the group consisting of OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, CF₃, OCF₃, NO₂, SO₂, SOR, SO₃R, halo, or alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl with one or more alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl being optionally substituted with one or more OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, OCF₃, CF₃, NO₂, SO₂, SOR, SO₃R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or a heterocyclic group, wherein R is independently alkyl, alkynyl, alkylaryl, aryl or cycloalkyl; and

(b) G is selected from the group consisting of BR₂, CR, CRR′, C (O) , C (O) R, C (O) OR, C (O) NR₂, O, NR, S, SR, SO₂, SOR, Si, P, P (=O) , S, Se or alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl with one or more alkyl, alkenyl, alkynyl, alkylaryl, aryl and cycloalkyl being optionally substituted with one or more OR, NR₂, SR, C (O) R, C (O) OR, C (O) NR₂, CN, CF₃, OCF₃, NO₂, SO₂, SOR, SO₃R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or a heterocyclic group, wherein R is independently alkyl, alkynyl, alkylaryl, aryl or cycloalkyl; and

(c) n is zero, a positive integer or a negative integer.
The method according to claim 18, wherein the gold (III) metal center comprises a light-emitting layer of a light-emitting device.
The method according to claim 18, wherein the gold (III) metal group comprises a layer of a light-emitting device.
The method according to claim 18, wherein the gold (III) metal compound is a dopant included in the light-emitting layer or emissive layer of the light-emitting device.
The method according to claim 18, wherein the gold (III) metal compound is a dopant included in a light-emitting device.
A light-emitting device with an ordered structure comprising an anode, a hole-transporting layer, a light-emitting layer, an electron-transporting layer and a cathode wherein the light-emitting layer comprises a gold (III) compound having:

(a1) a chemical structure represented by the following general formula (I) ,

wherein:

(a) ring A is coordinated to the Au atom through a nitrogen atom, and comprises a substituted or unsubstituted pyridyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted thienopyridinyl, a substituted or unsubstituted furopyridinyl group, a substituted or unsubstituted selenophenopyridinyl group;

(b) rings B and B’ are each coordinated to the Au atom through a carbon atom, and are each independently a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;

(c) each D is independently at each occurrence absent or a cyclic or acyclic moiety wherein: (ci) the cyclic moiety is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted polycyclic group, a substituted or unsubstituted acene, and a substituted or unsubstituted a heteroacene; and (cii) the acyclic moiety is selected from the group consisting of a substituted or unsubstituted alkynyl, a substituted or unsubstituted arylalkynyl, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted alkoxy, and a substituted or unsubstituted arylalkoxy;

(d) the dashed curved line in ring E is absent or present, wherein if the dashed curved line in ring E is absent, there is no bond connection between the ring structures D; if the dashed curved line in ring E is present, ring E is a substituted or unsubstitutedN-containing ring with ring size of 5-10 that may contain either one or more chemical moieties selected from -C (RR′) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′) -, -Se-, -As (R) , -CH=CH-and -CR=CR′-, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, thioether, selenoether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonate ester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(e) the dashed linear lines independently represent the absence or presence of a bond; B, B’, and each D, independently represent a substituted or unsubstituted monocyclic aryl, a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) , or a substituted or unsubstituted heteroaryl group; or D, Y, and B together and/or D, Y, and B’ together, independently form a substituted or unsubstituted fused polycyclic aryl (such as containing two or more fused aryl groups; at least one aryl group fused with at least one heteroaryl group; or at least one aryl fused with a cycloalkyl, cycloalkenyl, cycloalkynyl, or heterocyclyl group) ; X and Y are each independently at each occurrence absent or non-coordination sites selected from the group consisting of -C (RR′) , -C (=O) , -N (R) -, -O-, -P (R) -, -P (=O) R-, -B (R) -, -S-, -S (=O) -, -S (=O) ₂-, -Si (RR′) -, -Se-, -As (R) , -CH=CH-and -CR=CR′-, wherein R and R′ are independently selected from the group consisting of hydrogen, halogen, aryl, alkyl, heteroaryl, nitro, trifluoromethyl, cyano, arylether, alkylether, heteroaryl ether, diarylamine, dialkylamine, diheteroarylamine, diarylborane, triarylsilane, trialkylsilane, alkenyl, alkylaryl, cycloalkyl, haloformyl, hydroxyl, aldehyde, carboxamide, amine, amino, alkoxy, azo, benzyl, carbonateester, carboxylate, carboxyl, isocyanate, isocyanide, isothiocyanate, nitrile, nitro, nitroso, phosphine, phosphate, phosphono, pyridyl, sulfonyl, sulfo, sulfinyl, sulfhydryl, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl, a heterocyclic group and derivatives thereof;

(f) whereinp and q are each independently 0, 1, 2 or 3; andp and q are not both equal to 0; wherein (fi) whenp or q is equal to 0, there is no bond connection between the ring structures B and D, or B′ and D; (fii) when Y is absent andp or q is equal to 1, there is a single bond linked between the ring structures B and D, or B′ and D, respectively; (fiii) when Y is present andp or q is equal to 1, there is a single bond linked between Y and the ring structures B and D, or B′ and D;

(g) wherein r and s are each independently 1, 2 or 3; wherein (gi) when X is absent and s or r is equal to 1, there is a single bond linked between the ring structures A and B′, or A and B; (gii) when X is present and s or r is equal to 1, there is a single bond between X and the ring structures A and B′, or A and B;

(h) Z and Z’ are each a substituent on Ring B and B′, respectively, and are each independently selected from the group consisting of substituted or unsubstituted alkyl (e.g., substituted or unsubstituted C₁-C₁₀ alkyl) , substituted or unsubstituted haloalkyl (e.g., substituted or unsubstituted C₁-C₁₀ haloalkyl) , substituted or unsubstituted amine, substituted or unsubstituted alkoxy (e.g., substituted or unsubstituted C₁-C₁₀ alkoxy) , substituted or unsubstituted haloalkoxy (e.g., substituted or unsubstituted C₁-C₁₀ haloalkoxy) , substituted or unsubstituted alkylthio (e.g., substituted or unsubstituted C₁-C₁₀ alkylthio) , substituted or unsubstituted alkylselenyl (e.g., substituted or unsubstituted C₁-C₁₀ alkylselenyl) , hydroxyl, thiol, nitrile, nitro, F, Cl, Br, and I, and g and g’ are independently an integer between 1 and 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; wherein wheng or g’ is equal to 0, the substituent Z or Z’, respectively, is absent;

(i) n is zero, a positive integer or a negative integer; or

(a2) the compound according to any one of claims 2 to 9.
The light-emitting device of claim 23, wherein the light-emitting layer or emissive layer is prepared using vacuum deposition or solution processing technique.
An apparatus comprising:

the compound accordingly to any one of claims 1 to 9 or 17, and wherein the apparatus is selected from the group consisting of a television, a copier, a printer, a liquid crystal display, a measuring instrument, a display board, a marker lamp, an electrophotographic photoreceptor, a photoelectric transducer, a solar cell or an image sensor, such that the apparatus incorporates the compound for light emission purposes.