CN116655662A - Zinc-based organic-inorganic hybrid crystal based on piperidine and preparation method and application thereof - Google Patents

Abstract

The invention discloses a zinc-based organic-inorganic hybrid crystal based on piperidine, a preparation method and application thereof, wherein the crystal is (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ Which is crystallized in a chiral space group P2 in a monoclinic system ₁ In the method, a typical zero-dimensional stacking structure is presented, the crystal is obtained through a room temperature volatilizing crystallization mode, a middle infrared second-order nonlinear optical effect with certain intensity is presented, the frequency multiplication coefficient is 0.29 times of that of a commercial potassium dihydrogen phosphate (KDP) crystal, the method has a simple preparation method and good phase purity, and the method has potential application value in components such as a laser frequency converter, an electro-optic modulator, an electro-optic deflector and the like and related fields.

Description

A kind of zinc-based organic-inorganic hybrid crystal based on piperidine and its preparation method and application

technical field

The invention relates to an organic-inorganic hybrid crystal, in particular to a piperidine-based zinc-based organic-inorganic hybrid crystal, and also relates to a preparation method and application of the hybrid crystal.

Background technique

Functional materials refer to a class of materials with rich properties such as dielectric, piezoelectric, ferroelastic, ferroelectric, pyroelectric, nonlinear optics, etc., making them related to information storage, energy conversion, force-sensitive sensing, intelligent Switches and other high-tech fields, such as infrared detection, sonar systems, ignition devices, laser frequency converters, optical parametric oscillators and other practical application scenarios. Inorganic materials in the prior art have high energy consumption, complex preparation process, high toxicity, and mechanical flexibility that do not meet the needs of specific applications. Researchers need to find alternatives to overcome these shortcomings. As one of the feasible solutions, polymer materials represented by polyvinylidene fluoride (PVDF) and odd-numbered nylon exhibit strong piezoelectric and pyroelectric effects, good structural flexibility, and convenient membrane preparation processes. , but it is criticized for problems such as poor thermal stability and low crystallinity, which limit further development. In order to solve the difficulties faced by pure inorganic materials and polymer materials, organic-inorganic hybrid crystal materials have been successfully discovered to develop new flexible devices, portable wearable devices, biomimetic materials, biocompatible materials, etc.

As an important physical property in functional materials, nonlinear optics refers to the effects of optical frequency doubling, sum frequency, difference frequency and optical parameter oscillation when laser propagates in a medium with non-zero second-order polarizability. Materials with excellent properties can be used to prepare components such as laser frequency converters, electro-optic modulators, and electro-optic deflectors, and play an extremely important role in high-tech fields such as optical information processing, high-speed optical communications, optical information storage, and electronic instruments.

At present, organic-inorganic hybrid crystals with nonlinear optical effects have the advantages of light weight, rich chemical structure combinations, designability, and easy film production. However, the construction of existing second-order nonlinear optical effect materials is often carried out around molecular-based ferroelectrics. "; However, whether it is the modification of molecules or the introduction of chiral molecules, the above preparation methods require complex experiments and high prices to be realized, which greatly limits the application of organic-inorganic hybrid materials.

Contents of the invention

Purpose of the invention: the purpose of the present invention is to provide a piperidine-based zinc-based organic-inorganic hybrid crystal with strong mid-infrared second-order nonlinear optical effect, and the second purpose is to provide the above-mentioned piperidine-based zinc-based organic-inorganic hybrid crystal A method for preparing a hybrid crystal, and the third object is to provide the application of the above-mentioned piperidine-based zinc-based organic-inorganic hybrid crystal as a second-order nonlinear optical material.

Technical solution: The piperidine-based zinc-based organic-inorganic hybrid crystal of the present invention is (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ , and its chemical formula is C ₁₂ H ₂₆ Br ₄ Cl ₂ N ₂ Zn , belongs to the monoclinic crystal system, the space group is P2 ₁ , and the unit cell parameters are ^°

α=γ=90, β=93.065(4), Z=2,

Preferably, the organic cation is 4-chloro-1-methylpiperidine, which is dispersed around the ZnBr ₄ ^2- octahedron, and the overall structure is zero-dimensional stacked.

The method for preparing the above-mentioned piperidine-based zinc-based organic-inorganic hybrid crystal comprises the following steps:

(1) Add 4-chloro-1-methylpiperidine dropwise to water, and stir to obtain a mixed solution A;

(2) Add zinc bromide to mixed liquid A, and stir to obtain mixed solution B;

(3) Add hydrobromic acid aqueous solution to mixed solution B, react, stir until clear solution C;

(4) Solution C was evaporated at room temperature to obtain colorless transparent block crystals.

Preferably, in step (1), 5-8 mmol of 4-chloro-1-methylpiperidine is added per 100 mL of water, more preferably 5 mmol of 4-chloro-1-methylpiperidine is added per 100 mL of water.

Preferably, in step (2), 5-8 mmol of zinc bromide is added to every 100 mL of mixed solution A, more preferably 5 mmol of zinc bromide is added to every 100 mL of mixed solution A.

Preferably, in step (2), the molar ratio of 4-chloro-1-methylpiperidine to zinc bromide in the mixed solution B is 1:1~2, more preferably 4-chloro-1-methylpiperidine in the mixed solution B The molar ratio of methyl piperidine to zinc bromide is 1:1.

Preferably, in step (3), 10-15 mL of hydrobromic acid aqueous solution is added to every 100 mL of mixed solution B, and the hydrobromic acid in the hydrobromic acid aqueous solution accounts for 45-48% of the total mass of the solution.

Preferably, in step (4), the evaporation temperature of solution C is 20-30°C.

Application of the above-mentioned piperidine-based zinc-based organic-inorganic crystals as second-order nonlinear optical organic-inorganic hybrid materials.

Preferably, the second-order nonlinear optical organic-inorganic hybrid material is mainly used in components such as laser frequency converters, electro-optic modulators, and electro-optic deflectors.

Principle of the invention: (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ of the present invention is crystallized in the chiral space group P2 ₁ in the monoclinic crystal system, showing a typical zero-dimensional stacking structure, and the crystal passes through Obtained by volatile crystallization at room temperature, it exhibits a certain intensity of mid-infrared second-order nonlinear optical effect.

Protonated 4-chloro-1-methylpiperidine is interspersed between tetrahedral ZnBr ₄ ^2- , and under the weak interaction between the two, a zero-dimensional stacking structure is finally formed, with symmetry elements E and i, Belonging to point group 2 (C ₂ ), when the amine is protonated, the corresponding negatively charged clusters, ions, etc. need to be combined to achieve charge conservation. The interaction between the two makes the crystal crystallize in the chiral space group P2 ₁ , its second-order nonlinear optical susceptibility is non-zero, which in turn exhibits second-order nonlinear optical properties.

Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The hybrid crystal (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ of the present invention exhibits good mid-infrared second-order nonlinearity effect, its χ ⁽²⁾ is 0.29 times that of commercial potassium dihydrogen phosphate crystals, and has potential application value in components such as laser frequency converters, electro-optic modulators, and electro-optic deflectors; (2) the used in the preparation method 4-Chloro-1-methylpiperidine and zinc bromide are cheap and easy to obtain, environmentally friendly and non-toxic, and the preparation method is simple and the required time is short.

Description of drawings

Fig. 1 is the crystal structure diagram of (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ of the present invention;

Fig. 2 is the crystal asymmetric unit of (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ of the present invention;

Fig. 3 is the powder X-ray diffraction and simulation figure of (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ of the present invention;

Fig. 4 is a comparison diagram of the frequency doubling coefficient χ ⁽²⁾ of the present invention (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ and potassium dihydrogen phosphate crystal.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

(1) Add 5 mmol of 4-chloro-1-methylpiperidine dropwise to 100 mL of deionized water, and stir thoroughly;

(2) 5mmol of zinc bromide is added in the mixed liquid according to equimolarity with 4-chloro-1-methylpiperidine, fully stirred;

(3) 15mL of hydrobromic acid with a mass fraction of 48% was added to the mixed liquid, and fully stirred until clarification;

(4) Evaporate the clear solution at a room temperature of 30°C to obtain colorless and transparent bulk crystals (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ .

Crystals with a size of about 0.20×0.20×0.20 mm ³ were selected for single crystal structure analysis. The single crystal diffraction data were collected on a Bruker APEX-II CCD diffractometer. The crystal structure data of the obtained compounds are shown in Table 1.

The main crystallographic data of the compound (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ in Table 1

^[a] R ₁ ＝Σ||F _o |-|F _c ||/|F _o |. ^[b] wR ₂ ＝[Σw(F _o ² -F _c ² ) ² ]/Σw(F _o ² ) ² ] ^1/2 . ^[c] Maximum and minimum residual electron density.

The obtained colorless transparent bulk crystal has the chemical formula C ₁₂ H ₂₆ Br ₄ Cl ₂ N ₂ Zn at 223K, the crystal adopts the monoclinic system, the space group is P2 ₁ , and the unit cell parameters are α=γ=90°, β=93.065(4), Z=2, />

As shown in Figure 1, for the stacking structure, the entire crystal adopts a zero-dimensional stacking style, and the inorganic tetrahedron (ZnBr ₄ ) ^2- and the protonated organic 4-chloro-1-methylpiperidine pass through intermolecular forces, subtly fills the entire structure. As shown in Figure 2, the basic structural unit of the crystal is composed of an inorganic tetrahedron (ZnBr ₄ ) ^2- and a protonated organic 4-chloro-1-methylpiperidine.

Example 2

Diffraction experiments were carried out on the powder of colorless and transparent bulk crystals prepared in Example 1.

As shown in Figure 3, the characteristic peak 2θ is 11°, 11.6°, 12.5°, 13.7°, 18°, 19.2°, 19.9°, 20.9°, 21.6°, 23.3°, 24.5°, 25°, 25.6°, 26.4 °, 26.9°, 27.6°, 29.1°, 29.9°, 35.2°, which indicate that the powder diffraction experimental data of the obtained colorless transparent block crystals are completely consistent with the simulated data, indicating that the purity of the prepared compound is very high.

Example 3

The performance of the colorless transparent block (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ prepared in Example 1 was compared with that of commercial KDP.

First, the prepared colorless transparent block crystals are ground into a powder with a particle size of about 200-300 μm, then about 3-5 mg of powder samples are taken and clamped in a transparent glass sheet with a size of 1 cm × 1 cm, and then the glass The chip is placed on the optical path of the laser. The experiment uses Nd:YAG pulsed laser as the light source to generate 1064nm fundamental frequency light through the sample sandwiched by glass, and then the generated signal is displayed on the oscilloscope through the photomultiplier tube. Similarly, the reference KDP crystal was ground into a powder with a particle size of about 200-300 μm, and a comparative test was carried out under the same experimental conditions.

As shown in Figure 4, the macro frequency doubling coefficient χ ⁽²⁾ intensity comparison between (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ and commercial KDP is 0.29 times that of commercial KDP.

Claims (10)

1. A zinc-based organic-inorganic hybrid crystal based on piperidine, characterized in that the crystal is (4-chloro-1-methylpiperidine) ₂ ZnBr ₄ , and its chemical formula is C ₁₂ H ₂₆ Br ₄ Cl ₂ N ₂ Zn belongs to the monoclinic crystal system, the space group is P2 ₁ , and the unit cell parameters are ^° α=γ=90, β=93.065(4), Z=2, 2. The piperidine-based zinc-based organic-inorganic hybrid crystal according to claim 1, wherein the organic cation is 4-chloro-1-methylpiperidine, which is dispersed around the ZnBr ₄ ^2- octahedron , the overall structure is zero-dimensional stacking. 3. a method for preparing a piperidine-based zinc-based organic-inorganic hybrid crystal according to claim 1, characterized in that, comprising the following steps: (1) Add 4-chloro-1-methylpiperidine dropwise to water, and stir to obtain a mixed solution A; (2) Add zinc bromide to mixed liquid A, and stir to obtain mixed solution B; (3) Add hydrobromic acid aqueous solution to mixed solution B, react, stir until clear solution C; (4) Solution C was evaporated at room temperature to obtain colorless transparent block crystals. 4. The method according to claim 3, characterized in that, in step (1), 5-8 mmol of 4-chloro-1-methylpiperidine is added in every 100 mL of water. 5. The preparation method according to claim 3, characterized in that, in step (2), 5-8 mmol of zinc bromide is added in the mixed solution A of every 100 mL. 6. The method according to claim 3, characterized in that, in step (2), the molar ratio of 4-chloro-1-methylpiperidine and zinc bromide in the mixed solution B is 1:1-2. 7. the method for making according to claim 3 is characterized in that, in step (3), in the mixed solution B of every 100mL, add the hydrobromic acid aqueous solution of 10～15mL, the hydrobromic acid in the hydrobromic acid aqueous solution accounts for solution 45-48% of the total mass. 8. The method according to claim 3, characterized in that, in step (4), the temperature at which solution C evaporates is 20-30°C. 9. An application of the piperidine-based zinc-based organic-inorganic crystal according to claim 1 as a second-order nonlinear optical organic-inorganic hybrid material. 10. The application according to claim 9, wherein the second-order nonlinear optical organic-inorganic hybrid material is mainly used in laser frequency converters, electro-optic modulators or electro-optic deflectors.