CN115976648A - Crystal material and preparation method and application thereof - Google Patents

Abstract

The application discloses a crystal material and a preparation method and application thereof, belonging to the field of optical materials. A crystalline material of formula 2 (C) ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O；C ₃ N ₆ H ₆ Are connected by intramolecular hydrogen bond of N-H.N; (PF) ₆ ) ^‑ And C ₃ N ₆ H ₆ Three-dimensional structures are formed through intramolecular hydrogen bonding. The material is calculated by a first principle to show that the crystal has larger birefringence. Birefringence at 1042nm of 0.222; the birefringent crystal material has good transmittance in a broad-spectrum range of 200 nm-2500 nm.

Description

Crystal material and preparation method and application thereof

Technical Field

The application relates to a crystal material and a preparation method and application thereof, belonging to the field of optical materials.

Background

When one light beam strikes the crystal interface, two refracted light beams are generated, and this phenomenon is called birefringence. The cause of generation of birefringence is that due to anisotropy of the crystal material itself, a crystal capable of generating such a phenomenon is called a birefringence crystal. Crystals capable of generating birefringence are classified into uniaxial crystals and biaxial crystals, crystals of the trigonal, tetragonal or hexagonal system are uniaxial crystals, and crystals of the orthorhombic, monoclinic and triclinic systems are called biaxial crystals. Birefringent crystals are used in a wide variety of optical applications, such as in photolithography, telecommunications, and micromachining.

Birefringence crystals that have been commercially used at present include rutile crystals, lithium niobate crystals, yttrium vanadate crystals, calcite crystals, silica crystals, magnesium fluoride crystals, and α -BaB crystals ₂ O ₄ Crystals, and the like. The yttrium vanadate crystal is a crystal with excellent performance, but the ultraviolet cut-off edge is more than 400nm, and the transmittance of the yttrium vanadate crystal for the wavelength bands lower than 400nm is poor, so that the yttrium vanadate crystal cannot be applied to the ultraviolet deep ultraviolet band. The magnesium fluoride crystal has a longer transmission range (110 nm-8500 nm), is the only birefringent crystal capable of being used in ultraviolet deep ultraviolet band, but has a smaller birefringence, which seriously affects the application. Also beset by the magnitude of birefringence are silica crystals. And alpha-BaB ₂ O ₄ The crystal has a wide broad spectrum transmission range (189 nm-3500 nm), a short ultraviolet cut-off edge and a large birefringence (0.159 @253.7 nm), and has important application value in an ultraviolet region, but the crystal has phase change at high temperature, is extremely easy to crack in the growth process, and is not easy to obtain large-size single crystals.

With the development of science and technology, the requirement of birefringent crystals is higher and higher, and it is very important to find an excellent birefringent crystal from both qualitative and quantitative aspects. The excellent birefringent crystal is required to be easy to process and grow, and has a large birefringence and transmittance, and the physicochemical properties are stable, so researchers have been continuously searching and trying in recent years to find an excellent birefringent crystal material and use the material in practical applications.

Disclosure of Invention

According to one aspect of the present application, there is provided a crystalThe material is calculated by a first principle and shows that the crystal has larger birefringence. The birefringence at 1042nm was 0.222. The birefringent crystal material 2 (C) of the present invention ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O has good transmittance in a broad-spectrum range of 200 nm-2500 nm.

A crystalline material of formula 2 (C) ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O；

C ₃ N ₆ H ₆ Are connected by intramolecular hydrogen bond of N-H.N;

(PF ₆ ) ^- and C ₃ N ₆ H ₆ Three-dimensional structures are formed through intramolecular hydrogen bonding.

Optionally, the crystalline material is a single crystal structure.

Optionally, the crystal material belongs to monoclinic system, and the space group is P2 ₁ /n。

Optionally, the crystal material has unit cell parameters as follows:

α＝90°，β＝91.29°，γ＝90°。/>

optionally, the crystal material has a birefringence of 0.210-0.230 at 1042nm calculated by first principles.

According to a second aspect of the present application, a method of preparing a crystalline material is provided.

The preparation method of the crystal material comprises the following steps:

adjusting the pH value of a mixture containing melamine, a hexafluorophosphate compound and water to weak acidity, and reacting to obtain the crystal material;

the molar ratio of the melamine to the hexafluorophosphate compound is 2.5:1 to 3:1;

the molar volume ratio of the melamine to the water is 1mmol:15 mL-1 mmol:20mL.

Alternatively, the molar ratio of melamine to hexafluorophosphate compound is independently selected from 2.5: 1. 2.6: 1. 2.7: 1. 2.8: 1. 2.9: 1. 3:1, or a range of values between any two.

Alternatively, the molar volume ratio of melamine to water is independently selected from 1mmol:15mL, 1mmol:16mL, 1mmol:17mL, 1mmol:18mL, 1mmol:19mL, 1mmol: any value in 20mL, or a range of values between any two.

Optionally, the hexafluorophosphate compound is selected from LiPF ₆ 、NaPF ₆ 、KPF ₆ 、CsPF ₆ 、HPF ₆ At least one of (a).

Alternatively, the reaction conditions are as follows:

the temperature is 40-90 ℃;

the time is 10 min-20 min.

Optionally, the temperature of the reaction is independently selected from any of 40 ℃, 42 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 80 ℃, 90 ℃ or a range between any two.

Optionally, the time of the reaction is independently selected from any of 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min or a range between any two.

According to a third aspect of the present application, there is provided a use of a crystalline material.

The crystal material and/or the crystal material obtained by the preparation method are applied to the preparation of a polarization beam splitter prism or an optical element.

Optionally, the polarizing beam splitting prism is selected from one of a glan prism, a wollaston prism, a rochon prism, and a beam splitting polarizer;

the optical element is selected from one of an optical isolator, a circulator, a beam shifter, an optical polarizer, an optical modulator, an optical polarizer, a polarization beam splitter, a phase delay device and an electro-optical modulation device.

The beneficial effect that this application can produce includes:

1) This applicationThe crystal material provided by the invention is calculated by a first principle, and shows that the crystal has a larger birefringence. Birefringence at 1042nm of 0.222; the birefringent crystal material 2 (C) of the present invention ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O has good transmittance in a broad-spectrum range of 200 nm-2500 nm.

Drawings

FIG. 1 shows 2 (C) obtained in examples 1 to 3 ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ And the structure of the O crystal is shown schematically.

FIG. 2 shows 2 (C) obtained in examples 1 to 3 ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O crystal birefringence spectrum.

Fig. 3 is a schematic diagram of a polarizing beam splitting prism fabricated in example 4.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.

The analysis method in the examples of the present application is as follows:

the crystal structure data is tested by a four-circle diffractometer model Rigaku ROD, synergy Custom system, and the wavelength is Ga Ka ray

Carrying out data acquisition at room temperature;

the birefringence data of the crystal were calculated by the first principle. The calculation is carried out by adopting Materials Studio 8.0 software, and the setting parameters adopt default values without further adjustment.

Example 1

Preparation of 2 (C) by aqueous solution method ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ A method of O-birefringent crystals, comprising the steps of:

1) 3mmol of melamine and 1mmol of sodium hexafluorophosphate were dissolved in a clean beaker containing 20mL of water, and the pH of the solution was adjusted to weakly acidic

2) And (3) placing the mixed aqueous solution on a magnetic stirrer, heating to 60 ℃, and continuously stirring for 10min in the heating process. Then the mixture is placed at room temperature for cooling crystallization, and a large amount of colorless transparent single crystals appear after three or five days.

3) Washing the crystal obtained in the step 2) with purified water, naturally drying, placing the sample obtained in the example 1 on a four-circle diffractometer for collecting diffraction data, and reducing and refining the data through software to obtain a crystal structure as shown in figure 1. Containing two melamine rings, one water atom and one HPF in its asymmetric unit ₆ 。

4) Calculating the single crystal data obtained in the step 3) by using a first principle, and calculating by using the first principle to show that the compound has a larger birefringence. The birefringence at 1042nm is 0.222.

Example 2

Preparation of 2 (C) by aqueous solution method ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ A method of O-birefringent crystals, comprising the steps of:

1) Dissolving 2.8mmol of melamine and 1mmol of potassium hexafluorophosphate in a clean beaker filled with 18mL of water, and adjusting the pH value of the solution to weak acidity;

2) And (3) placing the mixed aqueous solution on a magnetic stirrer, heating to 50 ℃, and continuously stirring for 18min in the heating process. Then the mixture is placed at room temperature for cooling crystallization, and a large amount of colorless transparent single crystals appear after three or five days.

3) Washing the crystal obtained in the step 2) with purified water, naturally drying, placing the sample obtained in the embodiment 2 on a four-circle diffractometer for collecting diffraction data, and reducing and refining the data through software to obtain a crystal structure as shown in figure 1. Containing two melamine rings, one water atom and one HPF in its asymmetric unit ₆ 。

4) Calculating the single crystal data obtained in the step 3) by using a first principle, and calculating by using the first principle to show that the compound has a larger birefringence. The birefringence at 1042nm was 0.222.

Example 3

Preparation of 2 (C) by aqueous solution method ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ A method of O-birefringent crystals, comprising the steps of:

1) Dissolving 2.5mmol of melamine and 1mmol of lithium hexafluorophosphate in a clean beaker filled with 20mL of water, and adjusting the pH value of the solution to weak acidity;

2) And (3) placing the mixed aqueous solution on a magnetic stirrer, heating to 80 ℃, and continuously stirring for 10min in the heating process. Then the mixture is placed at room temperature for cooling crystallization, and a large amount of colorless transparent single crystals appear after three or five days.

3) Washing the crystal obtained in the step 2) with purified water, naturally drying, placing the sample obtained in the embodiment 3 on a four-circle diffractometer for collecting diffraction data, and reducing and refining the data through software to obtain a crystal structure as shown in figure 1. Containing two melamine rings, one water atom and one HPF in the asymmetric unit ₆ 。

4) Calculating the single crystal data obtained in the step 3) by using a first principle, and calculating by using the first principle to show that the compound has a larger birefringence. The birefringence at 1042nm was 0.222.

EXAMPLE 4 polarizing prism

Any 2 (C) obtained in examples 1 to 3 ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ The O crystal is processed into two mutually vertical crystals, and the two crystals are bonded to form a polarization beam splitting prism, when a light beam vertically enters the surface of the prism, O light and e light travel in the same direction at different speeds in the prism 1, when the light beam enters the prism 2 from the prism 1, the optical axis rotates by 90 degrees, and the O light becomes the e light and deviates from the discovery propagation; the e-light becomes o-light and travels close to the normal. After the two beams of light enter the air, the two beams of light are both transmitted to the light-thinning medium by the optically dense medium, so that two beams of linearly polarized light which are further separated can be obtained.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims (10)

1. A crystalline material, characterized in that it has the chemical formula 2 (C) ₃ N ₆ H ₆ )·HPF ₆ ·H ₂ O；

C ₃ N ₆ H ₆ Are connected by intramolecular hydrogen bond of N-H.N;

(PF ₆ ) ^- and C ₃ N ₆ H ₆ Three-dimensional structures are formed through intramolecular hydrogen bonding.

2. The crystalline material of claim 1, wherein the crystalline material is a single crystal structure.

3. The crystalline material of claim 1, wherein the crystalline material belongs to the monoclinic system and has a space group of P2 ₁ /n。

4. The crystalline material of claim 1, wherein the crystalline material has the following unit cell parameters:

α＝90°，β＝91.29°，γ＝90°。

5. the crystalline material of claim 1, wherein the crystalline material has a birefringence of 0.210-0.230 at 1042nm, calculated by first principles.

6. A method for preparing a crystalline material as claimed in any one of claims 1 to 5, characterized by comprising the steps of:

adjusting the pH value of a mixture containing melamine, a hexafluorophosphate compound and water to weak acidity, and reacting to obtain the crystal material;

the molar ratio of the melamine to the hexafluorophosphate compound is 2.5:1 to 3:1;

the molar volume ratio of the melamine to the water is 1mmol:15 mL-1 mmol:20mL.

7. The method according to claim 6, wherein the hexafluorophosphate compound is LiPF ₆ 、NaPF ₆ 、KPF ₆ 、CsPF ₆ 、HPF ₆ At least one of (1).

8. The method according to claim 6, wherein the reaction conditions are as follows:

the temperature is 40-90 ℃;

the time is 10min to 20min.

9. Use of the crystalline material according to any one of claims 1 to 5 and/or the crystalline material obtained by the production method according to any one of claims 6 to 8 for the production of a polarizing beam splitter prism or an optical element.

10. Use according to claim 9, wherein the polarizing beam splitting prism is selected from one of a glan prism, a wollaston prism, a rochon prism, a beam splitting polarizer;

the optical element is selected from one of an optical isolator, a circulator, a beam shifter, an optical polarizer, an optical modulator, an optical polarizer, a polarization beam splitter, a phase delay device and an electro-optical modulation device.

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