GB2027027A - Alkylbicyclo (2,2,2) octyl- phenyl-or-polyphenyl-nitriles, their use as liquid crystal compounds and materials and devices containing them - Google Patents
Alkylbicyclo (2,2,2) octyl- phenyl-or-polyphenyl-nitriles, their use as liquid crystal compounds and materials and devices containing them Download PDFInfo
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- GB2027027A GB2027027A GB7926902A GB7926902A GB2027027A GB 2027027 A GB2027027 A GB 2027027A GB 7926902 A GB7926902 A GB 7926902A GB 7926902 A GB7926902 A GB 7926902A GB 2027027 A GB2027027 A GB 2027027A
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- liquid crystal
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- 150000001875 compounds Chemical class 0.000 title claims abstract description 92
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 70
- 239000000463 material Substances 0.000 title claims abstract description 42
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 13
- 125000004432 carbon atom Chemical group C* 0.000 claims abstract description 9
- 239000000203 mixture Substances 0.000 claims description 43
- GPRLTFBKWDERLU-UHFFFAOYSA-N bicyclo[2.2.2]octane Chemical group C1CC2CCC1CC2 GPRLTFBKWDERLU-UHFFFAOYSA-N 0.000 claims description 9
- 230000000694 effects Effects 0.000 claims description 7
- 239000000758 substrate Substances 0.000 claims description 6
- 230000005684 electric field Effects 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 2
- 125000003545 alkoxy group Chemical group 0.000 claims 1
- 125000004802 cyanophenyl group Chemical group 0.000 claims 1
- -1 bromo compound Chemical class 0.000 abstract description 10
- 125000004093 cyano group Chemical group *C#N 0.000 abstract description 4
- DOBRDRYODQBAMW-UHFFFAOYSA-N copper(i) cyanide Chemical compound [Cu+].N#[C-] DOBRDRYODQBAMW-UHFFFAOYSA-N 0.000 abstract description 2
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical group CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 abstract description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 abstract description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 abstract 1
- 238000007796 conventional method Methods 0.000 abstract 1
- 230000018044 dehydration Effects 0.000 abstract 1
- 238000006297 dehydration reaction Methods 0.000 abstract 1
- 239000012071 phase Substances 0.000 description 14
- 230000007704 transition Effects 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 12
- 210000004027 cell Anatomy 0.000 description 11
- 238000004519 manufacturing process Methods 0.000 description 11
- 239000000047 product Substances 0.000 description 10
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 8
- 230000003098 cholesteric effect Effects 0.000 description 8
- LQNUZADURLCDLV-UHFFFAOYSA-N nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1 LQNUZADURLCDLV-UHFFFAOYSA-N 0.000 description 8
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- 239000004988 Nematic liquid crystal Substances 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 125000001147 pentyl group Chemical group C(CCCC)* 0.000 description 5
- KXDAEFPNCMNJSK-UHFFFAOYSA-N Benzamide Chemical compound NC(=O)C1=CC=CC=C1 KXDAEFPNCMNJSK-UHFFFAOYSA-N 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 4
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 4
- 235000019341 magnesium sulphate Nutrition 0.000 description 4
- 239000012044 organic layer Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- PKJBWOWQJHHAHG-UHFFFAOYSA-N 1-bromo-4-phenylbenzene Chemical group C1=CC(Br)=CC=C1C1=CC=CC=C1 PKJBWOWQJHHAHG-UHFFFAOYSA-N 0.000 description 2
- NGNBDVOYPDDBFK-UHFFFAOYSA-N 2-[2,4-di(pentan-2-yl)phenoxy]acetyl chloride Chemical group CCCC(C)C1=CC=C(OCC(Cl)=O)C(C(C)CCC)=C1 NGNBDVOYPDDBFK-UHFFFAOYSA-N 0.000 description 2
- 239000005711 Benzoic acid Substances 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical class CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 235000010233 benzoic acid Nutrition 0.000 description 2
- DIKBFYAXUHHXCS-UHFFFAOYSA-N bromoform Chemical compound BrC(Br)Br DIKBFYAXUHHXCS-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000004440 column chromatography Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 125000000740 n-pentyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000741 silica gel Substances 0.000 description 2
- 229910002027 silica gel Inorganic materials 0.000 description 2
- 229960001866 silicon dioxide Drugs 0.000 description 2
- CRWJEUDFKNYSBX-UHFFFAOYSA-N sodium;hypobromite Chemical compound [Na+].Br[O-] CRWJEUDFKNYSBX-UHFFFAOYSA-N 0.000 description 2
- 239000010421 standard material Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- FYSNRJHAOHDILO-UHFFFAOYSA-N thionyl chloride Chemical compound ClS(Cl)=O FYSNRJHAOHDILO-UHFFFAOYSA-N 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- 125000001140 1,4-phenylene group Chemical group [H]C1=C([H])C([*:2])=C([H])C([H])=C1[*:1] 0.000 description 1
- WPWHSFAFEBZWBB-UHFFFAOYSA-N 1-butyl radical Chemical compound [CH2]CCC WPWHSFAFEBZWBB-UHFFFAOYSA-N 0.000 description 1
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 1
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- 239000004990 Smectic liquid crystal Substances 0.000 description 1
- OCBFFGCSTGGPSQ-UHFFFAOYSA-N [CH2]CC Chemical compound [CH2]CC OCBFFGCSTGGPSQ-UHFFFAOYSA-N 0.000 description 1
- WETWJCDKMRHUPV-UHFFFAOYSA-N acetyl chloride Chemical compound CC(Cl)=O WETWJCDKMRHUPV-UHFFFAOYSA-N 0.000 description 1
- 239000012346 acetyl chloride Substances 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- PASDCCFISLVPSO-UHFFFAOYSA-N benzoyl chloride Chemical compound ClC(=O)C1=CC=CC=C1 PASDCCFISLVPSO-UHFFFAOYSA-N 0.000 description 1
- FKPSBYZGRQJIMO-UHFFFAOYSA-M benzyl(triethyl)azanium;hydroxide Chemical compound [OH-].CC[N+](CC)(CC)CC1=CC=CC=C1 FKPSBYZGRQJIMO-UHFFFAOYSA-M 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 229950005228 bromoform Drugs 0.000 description 1
- 210000002858 crystal cell Anatomy 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- NLUNLVTVUDIHFE-UHFFFAOYSA-N cyclooctylcyclooctane Chemical class C1CCCCCCC1C1CCCCCCC1 NLUNLVTVUDIHFE-UHFFFAOYSA-N 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 239000000374 eutectic mixture Substances 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000013213 extrapolation Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- ORUIBWPALBXDOA-UHFFFAOYSA-L magnesium fluoride Chemical compound [F-].[F-].[Mg+2] ORUIBWPALBXDOA-UHFFFAOYSA-L 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- 125000003136 n-heptyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000001624 naphthyl group Chemical group 0.000 description 1
- 125000002347 octyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- HRZFUMHJMZEROT-UHFFFAOYSA-L sodium disulfite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])(=O)=O HRZFUMHJMZEROT-UHFFFAOYSA-L 0.000 description 1
- 235000010262 sodium metabisulphite Nutrition 0.000 description 1
- 239000004296 sodium metabisulphite Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C255/00—Carboxylic acid nitriles
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
- C09K19/06—Non-steroidal liquid crystal compounds
- C09K19/32—Non-steroidal liquid crystal compounds containing condensed ring systems, i.e. fused, bridged or spiro ring systems
- C09K19/321—Compounds containing a bicyclo [2,2,2] octane ring
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Liquid Crystal Substances (AREA)
Abstract
A novel liquid crystal compound has the molecular structure <IMAGE> where R is an alkyl group, which may contain up to 18 carbon atoms and which may be normal or branched and may contain a chiral centre, <IMAGE> is a bicyclo (2,2,2) octane ring, <IMAGE> is a phenyl ring and CN is a cyano group, n being an integer greater than 0, preferably 1 or 2. The compounds may be obtained by conventional methods e.g. from the corresponding bromo compound by treatment with cuprous cyanide, or from the corresponding carboxylic acid amide by dehydration. Liquid crystal materials containing such compounds and devices employing such materials are described.
Description
SPECIFICATION
Liquid crystal compounds and materials and devices containing them
The present invention relates to liquid crystal compounds and materials and devices containing them.
In the field of displays there is a requirement for electro-optic devices having a low power consumption. Devices incorporating liquid crystal materials have been shown to satisfy this requirement because they have an electrically switchable molecular arrangement and a very large electrical resistance, and at the present time a considerable amount of interest is being shown in such devices for these reasons.
There are many known liquid crystal materials; some have been known for many years. Liquid crystal materials are organic materials which exhibit a liquid crystal phase in which the molecules are arranged over limited spatial ranges in an ordered structure.
The materials may be single compounds or mixtures of compounds.
According to the present invention there is provided a liquid crystal compound having the following molecular structure:
where R is an alkyl group,
is a bicyclo (2,2,2) octane ring
is a phenyl ring, CN is a cyano group and n is an integer greater than 0.
A compound (or compounds) having molecular structure (I) will be referred to as a compound (or compounds), as defined.
The alkyl group R preferably contains less than eighteen carbon atoms, eg one to ten carbon atoms, and may be normal or branched. If R is branched it may contain a chiral centre in which case the compound is optically active.
Preferably n is 1 or 2 so that the compound is either
By a 'liquid crystal compound' is meant a compound in one of the following two known categories:
(i) Compounds which normally exhibit a liquid crystal phase;
(ii) Compounds which do not normally exhibit a liquid crystal phase but which nevertheless usefully affect some aspect of liquid crystal behaviour when dissolved in other liquid crystal compounds.
Compounds in category (ii) show a 'monotropic' or 'virtual' liquid crystal to isotropic liquid transition at a temperature below the melting point of their solid phase. The monotropic or virtual transition may be detected respectively by rapid cooling of the liquid phase or by dissolving the compound in a material exhibiting a liquid crystal phase, observing the change in the transition to the isotropic liquid phase of the material by the addition and calculating the virtual transition temperature by extrapolation.
Compounds in category (ii) might for example be usefully dissolved in other liquid crystal compounds to extend or vary the liquid crystal temperature ranges of the compounds or to vary the molecular helical pitch (in the case of 'cholesteric' liquid crystals).
Material which exhibits a liquid crystal phase and either consists of or contains a compound as defined above will be referred to herein as a material 'as defined'.
The liquid crystal phase exhibited by the material as defined may be nematic, smectic or cholesteric.
For a nematic phase the compound as defined should have a normal alkyl group R whilst for a cholesteric phase the compound as defined should have a'branched alkyl group R containing a chiral centre.
Preferably compounds as defined are prepared from the intermediate bromo compound
eg by one of the following routes
A compound as defined may be mixed with one or more other compounds as defined to enhance its liquid crystal properties, eg to extend its liquid crystal temperature range.
For example the following are examples of such mixtures:
R1, R2, R3 = alkyl R1 = R2 Likewise, compounds as defined may be mixed with one or more of the compounds in the following categories:
where
is a cyclohexane ring, X is a 1,4 phenylene group
or a 4,4' biphenylyl group
or a 2,6 naphthyl group
and Y is CN, or R1, or OR1 or CO.O-XX-Y' where Y1 is CN, or R' or OR'; the definition of R' being the same as that of R.
According to another aspect of the present invention a liquid crystal device includes means for containing a region of liquid crystal material, a region of liquid crystal material contained in the containing means, wherein the liquid crystal material is material as defined above, and means for applying an external stimulus to the material to alter the molecular arrangement in the material.
The means for applying an external stimulus may for example be means for applying an electric field to the region.
The change in molecular arrangement produced by the external stimulus may be used to affect the transmission of electromagnetic radiation at any wavelength of interest through the material, for example, by changing the transmissitivity of the material or by changing the helical order of the material, if it is optically active.
According to another aspect of the invention, an electro-optic liquid crystal device includes two adjacent substrates at least one of which is optically transparent, a layer of liquid crystal material contained in the space between the substrates wherein the liquid crystal material is the material as defined above, and deposited on the inner facing surfaces of the substrates, a film of conducting material to allow an electric field to be applied across the layer. The electro-optic device may for example be a display device used, for instance, in an instrument such as a time watch or clock. The device may be of known 'twisted nematic' effect or '(cholesteric-to-nematic) phase change' effect types.
Examples of methods of preparing compounds as defined will now be described. In these examples 'MP' represents melting point, 'C-N' represents crystalline to nematic liquid crystal transition temperature and 'N-I' represents nematic liquid crystal to isotropic liquid transition temperature.
EXAMPLE 1
The intermediate compound 1-bromo-4-alkyl substituted bicyclo [2,2,2] octane which is used in the preparations described below may be prepared by the following route:
R defined as above
STEP Al : The production of 3-acetyl-1 ,5-dicyano-3 substituted pentane.
STEP Bl : The production of 3-acetyl-3-substituted pentane-l ,5-dicarboxylic acid.
STEP C1 :The production of 4-acetyl-4-substituted cyclohexanone.
STEP Dl: The production of 4-hydroxy-l-substituted bicyclo [2.2.2] octan-2-one.
STEP El:The production of 1 -hydroxy-4-substituted bicyclo [2.2.2] octane.
STEP Fl : The production of 1-bromo-4-substituted-bicyclo [2.2.2] octane.
All six of these steps may be carried out by methods essentially analogous to those for R=methyi and ethyl described by H. D. Holtz and L. M. Stock in the Preparation of 1 -Carboxy-4-Substituted Bicyclo [2.2.2] Octanes,J.Am. Chem. Soc, 86,5183(1964).
EXAMPLE 2
The production of 4-alkyl substituted 1 -(4'-cyano-4"-biphenylyl) bicyclo [2.2.2] octane by the following route:
R as defined above
STEP A2: The production of 1 (4'-bromo-4"-biphenylyl)-4-substituted bicyclo [2.2.2] octane.
A solution of 1 -bromo-4-substituted bicyclo [2.2.2] octane (0.0039 mole) in dry nitrobenzene (15 cm3) is added dropwise over a period of thirty minutes to a well stirred solution of crushed anhydrous aluminium chloride (0.0016 mole) and 4-bromobiphenyl (0.01 16 mole) in dry nitrobenzene (25 cm3) maintained at 800C under anhydrous conditions. The mixture is kept at this temperature for five hours.
It is then left stirring at room temperature, eg overnight. It is then added to a small amount of a hydrochloric acid/ice water mixture and stirred for about twenty minutes. The organic layer is separated off and steam distilled to remove the solvent and 4-bromobiphenyl. The residue is dissolved in toluene and the solution so formed is dried over magnesium sulphate. It is then filtered and evaporated to dryness under vacuum. The solid residue is crystallized from ethanol and toluene. When R=pentyl, the product of this step has C--N=1 92.00C and N-I=23 1 .20C.
STEP B2: The production of 1 -(4'-cyano-4"'-biphenylyl)-4-substituted bicyclo [2.2.2] octane.
A solution of l-(4'-bromo-4"-biphenylyl)-4-substituted bicyclo [2.2.2] octane (0.0019 mole) in dry 1 -methyl-2-pyrrolidinone (5 cm3) is heated at 1 800C with anhydrous copper (I) cyanide (0.0039 mole) for two hours under anhydrous conditions. The mixture is allowed to cool and then added to a solution of anhydrous iron (III) chloride (0.35 g) in water (5 cm3) with concentrated hydrochloric acid (0.5 cm3). This is stirred for twenty minutes at 500C and then water is added (50 cm3). This mixture is shaken several times with ether and then the combined organic layers are dried over magnesium sulphate. The solution is filtered and evaporated to dryness under vacuum. The product is purified by column chromatography using silica-gel with a chloroform/hexane mixture as eluant.It is finally crystallised from 2-methoxy-ethanol.
An example of such a product is:
C--N=1 59.70C.
N--1=269.3 OC. See also Table 2 below.
EXAMPLE 3
The production of 1 -[4'-cyanophenyl]-4-alkyl substituted bicyclo [2.2.2] octane by the following route:
R as defined above
STEP A3: The production of 1 -phenyl-4-substituted bicyclo [2.2.2] octane may be carried out by a reaction which is analogous to that described by S. Sotheeswara, Ph.D. Thesis, Hull University Library 1 967. When R=pentyl the product of this step has M.P.=370C.
STEP B3: The production of 4'-(4-substituted 1-bicyclo [2.2.2] octyl)acetophenone.
A solution of acetyl chloride (0.0077 mole) in dry nitrobenzene (3 cm3) is added dropwise to a well stirred solution of 4-substituted 1-phenylbicyclo [2.2.2] octane (0.007 mole) and crushed anhydrous aluminium chloride (0.0082 mole) in dry nitrobenzene (7 cm3) at 00 C. This solution is left stirring, eg overnight, at room temperature. It is then added to a small amount of a hydrochloric acid/ice/water mixture and stirred for 30 minutes. The organic layer is separated off and steam distilled. The solid residue is taken up in chloroform and the resultant solution dried over magnesium sulphate. it is then filtered and evaporated to dryness under vacuum to give a solid. This is crystallised from a methanol/ethanol mixture. When R=pentyl the product of this step has M.P.=81 OC.
STEP C3: The production of 4'-(4-substituted 1 -bicyclo [2.2.2] octyl)benzoic acid.
A solution of sodium hypobromite, prepared by dissolving bromine (0.0168 mole) in a solution of sodium hydroxide (0.0570 mole) in water (1 5 cm3) at OOC, is added to a well stirred solution of 4'-(4substituted 1-bicyclo [2.2.2] octyl)acetophenone, prepared in step B3, in dioxan (15 cm3). Throughout the addition and for thirsty minutes afterwards the temperature is maintained at 35-400C. The excess of sodium hypobromite is destroyed by adding a solution of sodium metabisulphite in water. More water is added and bromoform distilled from the reaction mixture. On cooling, the solution is acidified with concentrated hydrochloric acid and the precipitated product filtered off and washed with water.
The product was crystallised from a methanol/ethanol mixture. When R=pentyl the product of this step has C-N=226.70C; N-I=288.70C.
STEP D3: The production of 4'-(4-substituted 1-bicyclo [2.2.2] octyl)benzoylchloride.
A solution of 4'-(4-substituted-l-bicyclo [2.2.2] octyl)benzoic acid prepared in Step C3 (0.0017 mole) in dry toluene (10 cm3) is heated under reflux with thionyl chloride (1 cm3) for one hour under
anhydrous conditions and then allowed to cool. The mixture is evaporated to dryness'and then more dry
toluene (10 cm3) is added. The resultant solution is again evaporated to dryness under vacuum. The acid
chloride residue is used in the step E3 without further purification.
STEP E3:The production of 4'-(4-substituted l-bicyclo [2.2.2] octyl)benzamide.
A solution of the acid chloride prepared in step D3, in dry benzene (10 cm3) is added dropwise to a well stirred ammonia solution (10 cm3 d=0.88). The resultant precipitate is collected (with some difficulty) and washed with water. It is crystallised from a water/ethanol mixture at OOC. When R=pentyl the product of this step has M.P.=247.30C.
STEP F3:The production of 1-(4'-cyanophenyl)-4-substituted bicyclo [2.2.2] octane.
A solution of 4'-(4-substituted 1 -bicyclo [2.2.2] octyl)benzamide (0.0010 mole) in chloroform (18 cm3) is stirred for one hour with a solution of sodium hydroxide (0.0750 mole) in water (3 cm3) and 0.02 g of benzyltriethylammonium hydroxide. The mixture is gently heated for fifteen minutes in a warm water bath and then allowed to cool. Ether (40 cm3) and water (40 cm3) are added. The organic layer is separated off, washed with water and then dried over magnesium sulphate. The solution is filtered and evaporated to dryness under vacuum. The solid residue is purified by column chromatography using silica gel with chloroform as eluent. It is then crystallised from light petroleum (b.p. 40-60).
An example of the product of this step is
which has C--N=62"C, N-l=l 000C. (See also Table 1 below).
The following tables give examples of the liquid crystalline temperature ranges of compounds and mixtures embodying the invention. In the tables R represents a normal alkyl group having the stated composition, C-N represents solid crystal to nematic liquid crystal transition temperature (OC), C-I represents solid crystal to isotropic liquid transition temperature (OC) and N-I represents nematic to isotropic liquid transition temperature (OC).
Table 1 -- Compounds having the formula
R C-NorI N-I CH3 93 (C-I) (35)* C H 62.5 (C--l) (17)* n-C3H7 66.5 (C-N) 88 n-C4H9 75.5 (C-N) 85 n-C5H11 62 (C-N) 100 n-C6H,3 72 (C-N) 86 n-C7H15 61 (C-N) 95 ()* represents a monotropic 'virtual' transition temperature obtained by studying suitable binary mixtures of each compound with a standard material.
Further examples are
Optically active analogues,
may be prepared by an analogous route.
Table 2 -- Compounds having the formula
R C-Norl N-I CH3 198 (C-I) (170)*
R C-N or 1 N-I C2H5 188 (C-N) 221 n-C3H, 180.5(C-N) 276 n-C4Hg 173 (C-N) 271.5 n-C5H11 1 59 (C-N) 269 n-C6H,3 133 (C-N) 259 n-C7Has 141 (C-N) 250.5
( )* represents a monotropic 'virtual' transition temperature obtained by studying suitable binary mixtures of each compound with a standard material.
Further examples are
Optically active analogues eg
may be prepared by an analogous route.
Although departures from ideality are known, examples of eutectic or nearly eutectic mixtures embodying the invention are quoted (Tables 3-6) as exemplifying the application of the above compounds in Tables 1 and 2.
Table 3-The following mixture:
Mixture Constituent Mole % C-N n-c*7 wCN 51.0) 33.3 n~cs wCN 49.0) Table 4 - The following mixture:
Mixture Constituent Mole % C-N n-c3H7 MtCN 38.0) 20.8 n C5HII XC9 34.9) n-4sBwCN 27.1) Table 5-The following mixture:
Mixture Constituent Mole % C-N n-c*7 CN 37.9) 20.6 n + wCs 34.4) n-cswrsCN 27.0) n-49g v C 0.7) Table 6-The following mixture::
Mixture Constituent Mole % C-N n-csH7 won 19.9) -3.5 n-c5i 16.2) n-csw -CN 12.3) n-csH11 51.6) In addition the bicyclo-octane compounds embodying the invention may be mixed with any of the compounds in one or more of the other classes listed above.
A liquid crystal device embodying the invention will now be described by way of example only with reference to the accompanying drawings of which:
Figure 1 is an exploded view of a twisted nematic display;
Figure 2 is a front view of a watch having a twisted nematic liquid crystal display constructed as shown in Figure 1; and
Figure 3 is a sectional view of the display part of the watch in Figure 2 but drawn to an enlarged scale.
As shown in Figure 1 a 'twisted nematic' type display includes a polariser 1 arranged with its polarisation axis 2 vertical. A liquid crystal cell 3 comprises two glass slides 4, 5 containing a layer of liquid crystal 6, consisting basically of a nematic material which may contain a small proportion (eg 1%) of a cholesteric compound. Electrodes 7, 8 eg of tin oxide, are arranged on the inner faces of the slides 4, 5. Behind the cell 3 is an analyser or second polariser 11 arranged with its polarisation axis 12 horizontal. A brushed aluminium reflector 27 is behind the analyser 11.
Prior to assembling the cell the slides 4, 5 are coated on their inner faces with silicon monoxide or magnesium fluoride. This coating is formed by evaporating a stream of eg silicon monoxide onto the slide at an angle of about 50 to the surface as for example described in UK Patent Specification No.
1,454,296. On assembly the slides are arranged with the evaporation direction on the two slides 4, 5 at 900 to one another. With such a coating liquid crystal molecules at the coated surface lie in a single direction (parallel to the evaporation direction) and at an angle of about 250 to 350 typically about 300 to the slide surface. As a result the liquid crystal molecules progressively twist from one slide 4 to the other slide 5. Thus the plane of plane polarised light is rotated through 900 on passing through the cell 3 providing the direction 13 of the molecules at the surface of the slide 4, 5 is parallel (or perpendicular) to the polarisers axis 2, 12 respectively. Thus when zero voltage is applied to the cell light passes through the analyser 1, cell 3 and analyser 11, and is then reflected back to an observer 1 5.
When a suitable voltage is applied between the electrodes 7. 8the molecules between the electrodes are caused to align parallel to the applied field and light transmitted by the polariser is transmitted without rotation to the analyser 11. Since the polariser and analyser 11 are crossed no light is transmitted to the reflector and no light is reflected back to the observer at those parts of the cell 3 between electrodes 7, 8 which therefore appear dark on a lighter background. Thus by shaping each electrode 7, 8 into say seven discrete parts separately connectable to a voltage source the numbers 0 to 9 may be displayed.
In the watch display of Figures 2, 3 the electrodes 7, 8 are arranged to provide four seven bar numeric characters plus a period dot which may be arranged to pulse once per second.
The voltage required to align the molecules parallel to the applied field, is the "ON" state, is dependent on layer 6 thickness, materials used, temperature and surface treatment of the slides 4, 5. A typical thickness of layer is 12 ym. The material used must be stable over the temperatures of use ie ambient temperatures which can be assumed constant for comparison purposes. A surface treatment ie evaporation of silicon monoxide at 50 giving large tilt eg 300 of molecules reduces the voltage necessary to turn the cell "ON" at the expense of a degraded contrast or speed.
In typical watch displays using twisted nematic liquid crystal displays a 1.5 volt battery is used to drive the oscillator and logic circuits of the watch and an up converter is used to raise the voltage to 3.0 volts for operating the display.
Material embodying the invention suitable for use as the liquid crystal 6 is:
n -c5Hj{ XCN 10% by weight n-c5wil -CN (known) 89% by weight cHsCHeClHcw2ocN (known) 1% by weight C93 Liquid crystal compounds and mixtures embodying the invention may also be used in known phase change effect devices in which an optically active material is normally mixed with a nematic material to give a long helical Pitch cholesteric material which may be switched to a nematic state by the action of an electric field applied in a way similar to that described above in relation to the twisted nematic device. An example of a phase change effect device is described in UK Patent No. 1,433,130.
The compounds or mixtures embodying the invention may comprise either the nematic material (if R is n-alkyl) or the optically material (if R is a chiral alkyl group) or both to form the long pitch cholesteric material. The material may be dyed with any known suitable pleochroic dye to give enhanced contrast.
Compounds and mixtures embodying the invention are particularly suitable in phase change devices in view of their low birefringence.
The following mixtures are further examples demonstrating the usefulness of the compounds and mixtures embodying the invention in twisted nematic and cholesteric-to-nematic phase change effect devices.
Mixture 1
wt % N-I n-CaH7 HzCN 30 fl -cs 40 92.70C n-c7HlsXax Physical Properties of mixture 1
Birefringence (An) at 20C = 0.1 4
Dielectric Anistropy (AE) at 200C = 1 3.3 TwistedNematic Properties of Mixture 1
(i) Measurements made in a 7 ym, rubbed polymer aligned cell at 200 C.
V90 (450) = 1.35 V rms 32 Hz V50 (100) = 1.89 V rms 32 Hz V10 (100) = 2.66 V rms 32 Hz
Key: Vx (y) x = % Transmission, y = angle of incidence.
dv dt (10 80 C) = 13.4 mv/ C
(ii) Response Times Trite 347 msecs 3 V rms at 200C TDeC8y 101 msecs Mixture 2
wt % N-I n~c3H7 XcN 15 transition n -ji 20 660C n-c7Hj5 15 Merck ZLI 1052 (benzoate ester mixture) 50 Physical Properties of Mixture 2
Birefringence (An) at 2O0C = 0.14
Twisted Hema tic Properties of Mixture 2
(i) Measurements made in a 7,am, rubbed polymer aligned cell at 200C.
V90 (450) = 1.30 V rms at 32 Hz V50 (100) = 1.73 V rms at 32 Hz V10(100) = 2.28 V rms at 32 Hz
V90, V50 and V10 are the voltages for 90, 50 and 10% transmission respectively. The figures in brackets are the angles between the axis of measurement and the normal to the twisted nematic cell.
The rate of change of voltage with temperature
(ii) Response Time TRIBe 172 ms JC Decay 92 ms 3 V rms Mixture 3 (Long pitch Cholesteric) wt % Ch-I Mixture 1 96.4 transition)
+ 970C
Ch = cholesteric, I = Isotropic liquid, Pitch length = 5 Um.
Phase Change Properties
(i) Von = 7.8 V rms 12 jum cell with homeotropic boundary conditions, measured at 230C.
(ii) Response Tirnes
TRIB6 450 ms Decay 400 ms atl0V,230C
Claims (30)
1. A liquid crystal compound having a molecular structure
where R is an alkyl group and
is a bicyclo (2.2.2) octane ring, n being an integer greater than zero.
2. A liquid crystal compound as claimed in claim 1 and wherein R is an n-alkyl group having not more than 18 carbon atoms.
3. A liquid crystal compound as claimed in claim 1 and wherein R is a branched alkyl group having not more than 18 carbon atoms and containing a chiral centre.
4. A liquid crystal compound as claimed in claim 1 and wherein the integer n is one, the compound being a 1-[4' cyanophenyl]-4-alkyl substituted bicyclo [2.2.2] octane.
5. A liquid crystal compound as claimed in claim 1 and wherein the integer n is two, the compound being a 1-[4'-cyano-4"-biphenylyl]-4-alkyl substituted bicyclo [2.2.2] octane.
6. A liquid crystal compound as claimed in claim 4 and wherein R is an n-alkyl group having from 1 to 10 carbon atoms.
7. A liquid crystal compound as claimed in claim 4 and wherein R is an alkyl group having from three to 10 carbon atoms and containing a chiral centre.
8. A liquid crystal compound as claimed in claim 5 and wherein R is an n-alkyl group having from 1 to 10 carbon atoms.
9. A liquid crystal compound as claimed in claim 5 and wherein R is an alkyl group having from three to ten carbon atoms and containing a chiral centre.
10. A liquid crystal compound as claimed in claim 6 and wherein the compound is
11. A liquid crystal compound as claimed in claim 6and wherein the compound is
12. A liquid crystal compound as claimed in claim 6 and wherein the compound is
13. A liquid crystal compound as claimed in claim 6 and wherein the compound is
14. A liquid crystal compound as claimed in claim 6 and wherein the compound is
1 5. A liquid crystal compound as claimed in claim 6 and wherein the compound is
1 6. A liquid crystal compound as claimed in claim 6 and wherein the compound is 5
17.A liquid crystal compound as claimed in claim 8 and wherein the compound is
1 8. A liquid crystal compound as claimed in claim 8 and wherein the compound is
19. A liquid crystal compound as claimed in claim 8 and wherein the compound is
20. A liquid crystal compound as claimed in claim 8 and wherein the compound is
21. A liquid crystal compound as claimed in claim 8 and wherein the compound is 1
22. A liquid crystal compound as claimed in claim 8 and wherein the compound is
23. A liquid crystal compound as claimed in claim 8 and wherein the compound is
24. A liquid crystal material comprising a mixture of compounds at least one of which is a compound as claimed in claim 1.
25. A liquid crystal material comprising a mixture of compounds at least two of which are compounds as claimed in claim 1.
26. A liquid crystal material as claimed in claim 25 and wherein the mixture contains at least one compound of the form
and at least one compound of the form
where R', and R'2 are n-alkyl groups.
27. A liquid crystal material as claimed in claim 24 and wherein the mixture contains at least one compound of the form
where R'3 is an alkyl or alkoxy group.
28. An electro-optic liquid crystal device including two adjacent substrates at least one of which is optically transparent, a layer of liquid crystal material contained in the space between the substrates and, deposited on the inner facing surfaces of the substrates, a film of conducting material to allow an electric field to be applied across the layer and characterised in that the liquid crystal material includes a compound as claimed in claim 1.
29. A device as claimed in claim 28 and wherein the liquid crystal device is a twisted nematic effect device.
30. A device as claimed in claim 28 and wherein the liquid crystal device is a cholesteric-tonematic phase change effect device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7926902A GB2027027B (en) | 1978-08-04 | 1979-08-02 | Alkyl bicyclo (2,2,2)octyl-phenyl-or-polyphenyl-nitriles their use as liquid crystal compounds and materials and devices containing them |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7832350 | 1978-08-04 | ||
| GB7926902A GB2027027B (en) | 1978-08-04 | 1979-08-02 | Alkyl bicyclo (2,2,2)octyl-phenyl-or-polyphenyl-nitriles their use as liquid crystal compounds and materials and devices containing them |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2027027A true GB2027027A (en) | 1980-02-13 |
| GB2027027B GB2027027B (en) | 1982-12-15 |
Family
ID=26268459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7926902A Expired GB2027027B (en) | 1978-08-04 | 1979-08-02 | Alkyl bicyclo (2,2,2)octyl-phenyl-or-polyphenyl-nitriles their use as liquid crystal compounds and materials and devices containing them |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2027027B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2432546A1 (en) * | 1978-08-04 | 1980-02-29 | United Kingdom Government | COMPOUNDS AND MATERIALS HAVING LIQUID CRYSTAL PROPERTIES, AND DEVICES CONTAINING THEM |
| EP0085995A1 (en) * | 1982-02-04 | 1983-08-17 | MERCK PATENT GmbH | Anisotropic compounds and liquid crystal compositions |
| US4478740A (en) * | 1982-02-18 | 1984-10-23 | Merck Patent Gesellschaft Mit Beschrankter Haftung | Benzonitriles |
| EP1887069A1 (en) * | 2006-08-11 | 2008-02-13 | MERCK PATENT GmbH | Bicyclooctyl reactive mesogens |
-
1979
- 1979-08-02 GB GB7926902A patent/GB2027027B/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2432546A1 (en) * | 1978-08-04 | 1980-02-29 | United Kingdom Government | COMPOUNDS AND MATERIALS HAVING LIQUID CRYSTAL PROPERTIES, AND DEVICES CONTAINING THEM |
| EP0085995A1 (en) * | 1982-02-04 | 1983-08-17 | MERCK PATENT GmbH | Anisotropic compounds and liquid crystal compositions |
| US4514317A (en) * | 1982-02-04 | 1985-04-30 | Merck Patent Gesellschaft Mit Beschrankter Haftung | Anisotropic compounds and liquid crystal mixtures |
| US4478740A (en) * | 1982-02-18 | 1984-10-23 | Merck Patent Gesellschaft Mit Beschrankter Haftung | Benzonitriles |
| EP1887069A1 (en) * | 2006-08-11 | 2008-02-13 | MERCK PATENT GmbH | Bicyclooctyl reactive mesogens |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2027027B (en) | 1982-12-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 19990801 |