CN115785153B - A nitrogen-phosphine-mixed binuclear cuprous cluster luminescent material and its fluorescence sensing - Google Patents

Abstract

The invention discloses a binuclear cuprous cluster luminescent material mixed with nitrogen/phosphine ligands and a preparation method thereof, as well as VOC sensing application of the material. The luminescent material has a structural formula of ( _Xantphos ) _Cu2I2 (3-PhPy) ₂ , wherein Xantphos is an electrically neutral diphosphine ligand 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene, and 3-PhPy is a nitrogen-containing ligand 3-phenylpyridine. The luminescent material is prepared by a coordination reaction between CuI and a ligand through mechanical ball milling. The material itself has strong luminescence and can be used as a luminescent material. After the material is placed in a pyridine or cyclohexylamine atmosphere, different fluorescence sensing responses of maximum luminescence intensity shift or fluorescence quenching are respectively presented. The material is easy to prepare and has good solubility and stability, and is also easy to prepare into a paper-based loaded or polymer-doped fluorescence sensing film, and the film also exhibits rapid and selective response and sensitive recognition fluorescence sensing performance.

Description

A nitrogen-phosphine-mixed binuclear cuprous cluster luminescent material and its fluorescence sensing

Technical Field

The invention relates to the technical field of luminescent materials, in particular to the field of photoluminescent materials, and in particular to the field of fluorescent sensing materials.

Background technique

Volatile Organic Compounds (VOCs) are an important component of air pollution. They are abundant in sources, diverse in types, and mostly toxic and hazardous. Long-term exposure to VOC atmospheres can cause harm to human health. However, due to the low concentration of VOCs in the environment, slow volatilization, and difficult-to-detect symptoms, there are still many difficulties in detecting VOCs.

With the rapid development of social economy, various pollutions are becoming increasingly serious. For example, industrial waste gas emission pollution and various building and decoration materials used in the real estate industry have caused air pollution problems. VOC is the main factor of indoor air pollution. Its specific components include benzene series, organic chlorides, Freon series, pyridine compounds, etc. Its sources are mainly coatings, wallpapers, floor tiles, insulation materials, adhesives, etc. in indoor decoration materials and furniture. In order to understand the status of VOC in the air, it is very important to detect it. The existing methods are: gas chromatography (GC), high performance liquid chromatography (HPLC), electrochemical sensing, atomic absorption spectroscopy, etc. However, these methods have certain shortcomings, such as complex instruments, difficult to carry, cumbersome procedures, high cost, long detection time, sample consumption, secondary pollution, etc.

Compared with traditional detection methods, fluorescence sensing detection methods are gaining more and more attention. Because fluorescence sensors have the advantages of high sensitivity, rich signal collection, stable signals, easy miniaturization of instruments, and easy use, their development is also steadily advancing towards full practical application. Fluorescence sensors are mainly divided into two categories: thin-film fluorescence sensors that are easy to reuse and can sense and respond to gas-phase substances, and homogeneous fluorescence sensors used in solutions. The main structure of a fluorescence sensor is usually composed of the following three parts: a receptor for foreign substances, a reporter, and a connector. In the entire fluorescence sensor structure, the role of the receiver is to receive foreign molecules and convert signals. Therefore, the selection and preparation process of the receptor material (that is, the sensitive material) is crucial, which directly determines the performance and application range of the sensor.

According to the material type of the sensing material, fluorescent sensors can be divided into biosensors, inorganic material sensors and organic material sensors. But each has its own advantages and disadvantages. Biomaterial sensors generally use enzymes and microorganisms as sensing materials, and are mainly used in the biological and medical fields, and are less used in other fields. Inorganic materials used for sensing are mainly semiconductor materials, metals and ceramics, which are usually used for pressure and temperature sensing. However, due to their too dense internal structure, the luminescence center is difficult to be affected by the external atmosphere, and they are rarely used in gas and water source detection. Organic material sensors have been gradually applied to VOC fluorescence sensing because of the diverse organic molecular structures and properties, which are easy to design and optimize. However, the fluorescence of organic materials is greatly affected by molecular stacking, such as the aggregation-induced fluorescence quenching (ACQ) phenomenon is the most prominent manifestation. Overall, organic material sensors are still in the development stage.

According to a large number of existing research reports, it can be found that the complex can form a hybrid material with good stability through the coordination hybridization of inorganic and organic materials, and can show the function of fluorescence sensing, so it is a better solution to organically combine the advantages of inorganic and organic materials. Wenger once reviewed the vapor color change phenomenon of the complex and the application prospects of VOC sensing, predicting that this is a simple and cheap solution (Chemical Reviews 2013, 113 (5), 3686-3733). However, as mentioned in the article, researchers in this field usually only study the molecular mechanism of the phenomenon, and ignore the quantitative and cheap application requirements of actual sensing detection. The platinum and gold used in the complexes reported at present are expensive, which limits their wide application. Compared with other metals, copper has the advantages of being cheap, environmentally friendly, and non-toxic. It is abundant in the earth's crust, and my country's copper resource reserves rank third in the world. From the existing research reports, it can be seen that cuprous complexes are not only based on cheap metals, but also have good luminescence properties. Moreover, the luminescence properties can be regulated by structure (such as the regulation of luminescence wavelength and quantum yield, etc.). Therefore, it can be speculated that cuprous complexes are a very promising molecular development platform for VOC fluorescence sensing detection. The current key issue is to find and develop cuprous complex sensing materials with VOC fluorescence response properties, so as to promote the widespread application of VOC fluorescence sensing technology.

Summary of the invention

The purpose of the present invention is to provide a new binuclear cuprous cluster luminescent material, a preparation method and application thereof, and the sensing application of the material to pyridine and cyclohexylamine VOC. The binuclear cuprous cluster complex luminescent material with good thermal stability is conveniently and cheaply prepared by the coordination reaction of cuprous iodide and two ligands under mechanical ball milling conditions, and it is found that the binuclear cuprous cluster complex luminescent material can rapidly and selectively perform significant fluorescence response in pyridine and cyclohexylamine atmospheres, and can be used for fluorescence sensing detection applications.

One of the technical solutions of the present invention is to provide a new binuclear cuprous cluster luminescent material, which is obtained by a coordination reaction between CuI, a chelated phosphine ligand Xantphos and a terminal nitrogen-containing ligand 3-PhPy under mechanical ball milling conditions, and has a molecular structure of (Xantphos) _Cu2I2 (3-PhPy) ₂ , wherein Xantphos is an electrically neutral diphosphine ligand 4,5-bis(diphenylphosphine)-9,9 _- dimethylxanthene, and 3-PhPy is a nitrogen-containing ligand 3-phenylpyridine.

The binuclear cuprous cluster luminescent material is a triclinic crystal system with a P-1 space group and a unit cell parameter of α＝86.946(2)°，β＝77.009(2)°，γ＝86.351(2)°， Z＝2， _DC ＝1.533g/ ^cm3 ，the crystal color of the material is yellow; the structure of the material is binuclear neutral complex, two cuprous ions adopt different tetrahedral coordination modes, and form a double tetrahedral structure connected by sharing two bridging iodine ions; one cuprous in the structure adopts _CuI2P2 tetrahedral coordination mode, in which two I are bridging iodine ions, and two P come from a diphosphine ligand Xantphos; the other cuprous in the structure adopts _{CuI2N2 tetrahedral} coordination mode, in which two I are bridging iodine ions, and two N come from two nitrogen-containing ligands 3-PhPy respectively; and there are strong supramolecular interactions between adjacent molecules, one of which is that the two _diphosphine ligands in the adjacent molecules form intermolecular CH···π interactions through the benzene ring and the xanthene ring, and the other is that the two 3-PhPy ligands in the adjacent molecules form strong intermolecular π···π stacking interactions through the benzene ring, all of which increase the structural rigidity inside the material; its molecular structure is as shown in formula (Ⅰ):

The binuclear cuprous cluster luminescent material is a high-efficiency luminescent phosphor with wide spectrum excitation, which emits strong green fluorescence under the excitation of ultraviolet light and visible light in the wavelength range of 250 to 450 nanometers, with a maximum luminescent wavelength of 540 nanometers and a color coordinate value of (0.3899, 0.5280). It can be used as a photoluminescent green light material or a green light material of the luminescent layer in an electroluminescent device composed of multiple layers of organic materials.

The second technical solution of the present invention is to provide a method for preparing a binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) _2. The preparation method is achieved by allowing CuI to fully coordinate with ligands Xantphos and 3-PhPy under mechanical ball milling conditions, and finally taking out the product powder. The specific implementation scheme is divided into four steps:

(1) CuI powder and ligand Xantphos and 3-PhPy powders were weighed and added into a ball mill at room temperature;

(2) Add ball milling balls into the ball milling jar with a ball-to-material ratio of 70:1, and then add 3 mL of acetonitrile;

(3) placing the ball mill jar into a ball mill, setting the ball mill speed to 160 rpm, and ball milling for 4 hours;

(4) After the ball milling is completed, the ball mill is placed in a vacuum oven at 40°C for drying, and the resulting powder is the product;

(5) The molar ratio of the three reactants is 1:2:2, and the ball mill is an agate mill with a volume of 50 mL.

The third technical solution of the present invention is to provide a fluorescent sensing application of a binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ ; after placing the luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ in an environment containing pyridine VOC vapor, its maximum luminescence wavelength will undergo an obvious blue shift (the new maximum emission wavelength is 527nm), and the luminescence changes from the original green to blue-green, so it can be used as a sensing material for detecting pyridine VOCs.

A fourth technical solution of the present invention is to provide an application of a fluorescent sensing film of a binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ ; when the fluorescent sensing film is placed in an environment containing pyridine vapor, the maximum luminescence wavelength will quickly show an obvious blue shift phenomenon (the new maximum emission wavelength is 527 nm), and the luminescence changes from the original green to blue-green, so it can be used as a sensing film for detecting pyridine VOC; in addition, when the fluorescent sensing film is placed in an environment containing cyclohexylamine vapor, it will quickly show a significant fluorescence quenching response effect, and the fluorescent sensing film does not show obvious fluorescence response behavior to many VOC vapors such as triethylamine, trimethylamine, ethanolamine, monomethylamine, benzene, 2-phenylpyridine, 3-phenylpyridine, 2-aminopyridine, 4-hydroxypyridine, diethylenetriamine, ammonia water, etc., so it can also be used as a selective fluorescent sensing film for detecting cyclohexylamine VOC.

The fifth technical solution of the present invention is to provide a method for preparing a fluorescent sensing film of a binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) _2. The preparation method is achieved by dissolving the binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ and then coating the solution on a cellulose film. The specific implementation scheme is divided into four steps:

(1) Dissolve the luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ powder in dichloromethane at room temperature;

(2) The cellulose film is made into a desired shape for convenient application to become a test paper base paper;

(3) coating the above-mentioned luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ solution on the test paper at room temperature;

(4) Finally, the coated test paper is dried under vacuum conditions, and after drying, a paper-based fluorescent sensing film is obtained.

The sixth technical solution of the present invention is to provide a method for preparing a fluorescent sensor film doped with a binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) _2. The binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ is embedded in PMMA (polymethyl methacrylate). The specific implementation scheme is divided into four steps:

(1) Dissolve PMMA solid in dichloromethane at room temperature;

(2) dissolving the luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ powder in dichloromethane at room temperature;

(3) mixing the above two solutions and stirring them to allow them to react fully to obtain a clear solution A;

(4) The clear solution A is spin-coated on a quartz plate, a metal substrate, or coated on a substrate such as a test paper at room temperature, and then dried to obtain a doped fluorescent sensing film.

The beneficial effects of the present invention are, firstly, _{the provided binuclear cuprous cluster luminescent material (Xantphos)Cu2I2(3-PhPy)2 , wherein} the introduced bulky chelated phosphine ligand Xantphos and the nitrogen ligand 3-PhPy based on phenylpyridine, as well as the presence of the rigid _{Cu2I2 binuclear} cuprous iodide cluster core are all conducive to molecular excited state luminescence, and quantum chemical calculations show that the luminescence of the material comes from the charge transfer excited state from the cluster core to the nitrogen-containing ligand, the charge separation characteristics of the excited state are significant, and the problem of excited state configuration distortion commonly existing in cuprous complexes is effectively avoided, thus being conducive to the luminescence of the material; in addition, there is a strong supramolecular effect between adjacent molecules in the material structure, all of which increase the structural rigidity inside the material, and also make the molecular structure exhibit good fluorescence emission performance, and also provide a basis for subsequent sensing performance research; the complex material has the advantages of being cheap and easy to purify, and also has good solubility and thermal stability, providing technical support for the further application of the material.

The beneficial effects of the present invention are as follows: secondly, the fluorescent sensing application of the binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ that selectively responds to pyridine, and this response can be completed rapidly in a short time; the fluorescent performance of the luminescent material after responding to pyridine is very good, and a very small amount of material powder can emit strong fluorescence, so only a small amount of fluorescent powder is needed in practical application, which is convenient for reducing the application cost, and the easy-to-operate doping approach also provides convenience for the cost control of the application; and after the material prepared by the same process is placed in a pyridine atmosphere, the sensing response characteristics of color change can be quickly observed; and its solubility and stability performance are very good, which is convenient for use as a fluorescent sensing material.

The beneficial effect of the present invention is again that the binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ has a fluorescence sensing application that selectively responds to cyclohexylamine, and this response can be completed rapidly in a short time; the fluorescence of the luminescent material after responding to cyclohexylamine can be completely quenched, and the degree of quenching is directly related to the amount of cyclohexylamine, and the quenching response performance has good reversibility, which is easy to reuse the material and the sensor, and also provides convenience for the cost control of the application; and after the material prepared by the same process is placed in a cyclohexylamine atmosphere, the sensing response characteristics of fluorescence quenching can be quickly observed; and its solubility, stability and reversible response performance are all very good, which is convenient for use as a fluorescence sensing material.

The beneficial effect of the present invention is again the VOC sensing application of the paper-based fluorescent film of the binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ provided. The use of the paper-based fluorescent film is as simple as that of a general gas detection test paper. In specific application, after the paper-based fluorescent film is placed in an environment with a pyridine or cyclohexylamine atmosphere for a short time, the film is irradiated with an ultraviolet light source, and it can be observed that the film rapidly has fluorescence enhancement and color change/fluorescence quenching phenomena, and the increase in VOC concentration shows an intensity-dependent fluorescence response effect, showing reversible rapid response and sensitive recognition fluorescence sensing performance, so it can be used as a portable fluorescent sensor test paper device for VOC detection; the fluorescent sensor film can be flexibly manufactured into various required shapes, is very light, is very easy to carry, and is also easy to prepare, providing technical support for the further application of luminescent materials.

The beneficial effect of the present invention is again the VOC sensing application of the doped fluorescent film of the binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ provided. The doped fluorescent film can be made on various substrates such as quartz, plastic, paper, etc., and can also be directly coated on the optical fiber port to make an optical fiber sensing probe. In specific application, after the doped film is placed in an environment with pyridine or cyclohexylamine atmosphere for a short time, the film is irradiated with an ultraviolet light source, and it can be observed that the fluorescence is rapidly enhanced and the color changes/fluorescence quenching phenomena occur. In addition, the increase in VOC concentration shows an intensity-dependent fluorescence response effect, showing reversible rapid response and sensitive recognition fluorescence sensing performance. Therefore, it can be used as a sensitive film component of an optical fiber sensor for VOC detection.

The beneficial effects of the present invention are finally a method for preparing a binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ and its sensing film, which has the advantages of simple process, simple equipment, easy to obtain raw materials, cheap and easy to obtain raw material 3-PhPy, low production cost, high material preparation yield, and a large number of products can be obtained in a very short time, which is easy to promote.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1. Crystallographically independent unit structure of the binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ .

Figure 2. Supramolecular dimer structure of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ molecule.

Figure 3. Stacking diagram of binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ molecules in a unit cell and its surrounding space.

Figure 4. X-ray powder diffraction spectrum of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ : (a) is the spectrum obtained by calculation and simulation based on the single crystal structure data in Example 2; (b) is the spectrum of the powder obtained in Example 1 of the present invention.

Figure 5. Infrared absorption (FTIR) spectrum of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ .

FIG6 . Ultraviolet-visible (UV-Vis) absorption spectrum of the binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ .

FIG. 7 . Fluorescence emission (PL-EM) spectrum of polycrystalline powder of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ under 365 nm ultraviolet light excitation.

FIG8 . Fluorescence excitation (PL-EX) spectrum of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ polycrystalline powder at an emission light monitoring wavelength of 645 nm.

Figure 9. Frontier orbital diagram of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ molecule, clearly showing the charge transfer characteristics from the cluster core to the nitrogen-containing ligand.

Figure 10. Fluorescence emission spectra of the paper-based film loaded with binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ before and after a certain period of response in a pyridine atmosphere; in the figure, s represents the time unit in seconds, and min represents the time unit in minutes.

FIG. 11 . A graph showing the fluorescence emission wavelength shift (blue shift) during the response of a paper-based film loaded with a binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ in a pyridine atmosphere.

Figure 12. Fluorescence emission intensity change spectrum of the polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film after responding to a cyclohexylamine atmosphere for a certain period of time; in the figure, s represents the time unit second, and min represents the time unit minute.

FIG. 13 . Time kinetic curve of the fluorescence quenching process of the polymer-based fluorescent sensing film doped with binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ in response to cyclohexylamine atmosphere.

Figure 14. Selective recognition response of the polymer-based fluorescent sensing film doped with binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ to cyclohexylamine in various VOC atmospheres, that is, the selective fluorescence quenching response diagram.

Figure 15. Fluorescence enhancement response of the polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film in different concentrations of pyridine atmosphere and its fitting working curve.

Figure 16. Fluorescence quenching response of the polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film in different concentrations of pyridine atmosphere and the working curve obtained by fitting.

Figure 17. Fluorescence quenching response of the polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film in atmospheres of different cyclohexylamine concentrations and the working curve obtained by fitting.

Detailed ways

The implementation process of the present invention and the performance of the material are illustrated by the following examples:

Example 1

The polycrystalline powder of the synthesized binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ is prepared by using Xantphos, cuprous iodide and 3-PhPy as raw materials according to the following method: 0.3 mmol of Xantphos, 0.6 mmol of cuprous iodide and 0.6 mmol of 3-PhPy are weighed and placed in a ball mill, 17 g of ball milling balls are placed in the ball mill, and there are two types of agate ball milling balls, with diameters of 10 mm and 6 mm, respectively. 8 large balls and 14 small balls are added respectively, and then 3 ml of acetonitrile is added as a liquid grinding aid. The ball mill is milled at a speed of 160 rad/min for 4 hours; after ball milling, the product is placed in a vacuum oven at 40 degrees Celsius for drying to obtain a polycrystalline powder, and the yield (calculated as cuprous iodide) is 79.18%. After the complex luminescent material is placed in a pyridine atmosphere, it can be observed that the fluorescence emission quickly changes from green to blue-green light.

Example 2

Synthesis of single crystal of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) ₂ : The complex powder was dissolved in dichloromethane, and the solution was dripped into a test tube, and then n-hexane was slowly added as a precipitant. A milky white layer was formed at the interface. The sample was sealed with plastic wrap and sealing film and placed on a sample rack. A large number of yellow granular crystals were obtained in the test tube after a few days. A yellow granular crystal with a size of 0.42mm*0.32mm*0.20mm was selected for X-ray single crystal structure testing. The molecular structure of the compound is shown in Figures 1 and 2, and its unit cell stacking structure is shown in Figure 3.

A series of tests were conducted on the pure phase crystal sample of binuclear cuprous cluster luminescent material (Xantphos) Cu ₂ I ₂ (3-PhPy) _2. Steady-state fluorescence test was conducted on the crystal sample of the material of the present invention, and the results showed that the material can emit strong green light under different excitation wavelengths in the wavelength range of 250 to 450 nanometers, and the color coordinate value is (0.3899, 0.5280). The specific excitation spectrum and emission spectrum are shown in Figures 7 and 8. It can be seen that the material can be applied to green luminescent materials excited by multiple wavelengths, and can be used as photoluminescent green light materials, or light-emitting layer green light materials in electroluminescent devices composed of multi-layer organic materials.

Example 3

Preparation of fluorescent sensing film loaded with binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ and its atmospheric response: Weigh 0.045g of luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ and dissolve it completely in 7mL of dichloromethane. The solution is light orange, clear and transparent, and filtered. Cut the cellulose film into a size and shape suitable for the application by cutting and other methods, and use it as the test paper base paper used in the subsequent process; take an appropriate amount of filtrate and apply the filtrate on the test paper base paper by printing, dipping or brushing; dry the coated test paper under vacuum conditions (60℃, 30min), and obtain the fluorescent sensing film (fluorescent test paper) after drying; then put the sensing film into VOC to respond and test the fluorescence spectrum. The results show that when the fluorescent sensor film is placed in an environment containing pyridine vapor, the maximum emission wavelength will quickly show a blue shift phenomenon (the new maximum emission wavelength is 527nm), and the emission will change from the original green to blue-green, so it can be used as a sensor film (test paper) for detecting pyridine VOC; in addition, when the fluorescent sensor film is placed in an environment containing cyclohexylamine vapor, it will quickly show a significant fluorescence quenching response effect, and the paper-based fluorescent sensor film does not show obvious fluorescence response behavior to many VOC vapors such as triethylamine, trimethylamine, ethanolamine, monomethylamine, 2-phenylpyridine, 3-phenylpyridine, 2-aminopyridine, diethylenetriamine, diisopropylamine, and ammonia, so it can also be used as a selective fluorescent sensor film (test paper) for detecting cyclohexylamine VOC. (See Figures 10 and 11).

Example 4

Preparation of polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film and its atmospheric response: Weigh 0.8g of PMMA (polymethyl methacrylate, glass transition temperature: 105℃) and dissolve it completely in 9mL of dichloromethane. The solution is colorless, clear and transparent. 0.040g of luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ is completely dissolved in 6mL of dichloromethane. The solution is light green, clear and transparent. Slowly introduce the luminescent material solution into the PMMA solution. The solution is clear and transparent. Spin coat (1200rad/min) on a clean quartz wafer, dry (60℃, 30min), then put it into VOC for response, and test the fluorescence spectrum. The results show that when the fluorescent sensor film is placed in an environment containing pyridine vapor, the maximum emission wavelength will quickly show a blue shift phenomenon (the new maximum emission wavelength is 527nm), and the emission changes from the original green to blue-green, so it can be used as a sensor film for detecting pyridine VOC; in addition, when the fluorescent sensor film is placed in an environment containing cyclohexylamine vapor, it will quickly show a significant fluorescence quenching response effect, and the fluorescent sensor film does not show obvious fluorescence response behavior to many VOC vapors such as triethylamine, trimethylamine, ethanolamine, monomethylamine, 2-phenylpyridine, 3-phenylpyridine, diethylenetriamine, diisopropylamine, and ammonia, so it can also be used as a selective fluorescent sensor film for detecting cyclohexylamine VOC. (See Figures 12, 13, 14, 15, and 16).

Example 5

Preparation of polymer-based doped binuclear cuprous cluster luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ fluorescent sensing film and its atmospheric response: Weigh 0.8g of PMMA (polymethyl methacrylate, glass transition temperature: 105℃) and dissolve it completely in 9mL of dichloromethane. The solution is colorless, clear and transparent. 0.040g of luminescent material (Xantphos)Cu ₂ I ₂ (3-PhPy) ₂ is completely dissolved in 6mL of dichloromethane. The solution is light orange, clear and transparent. Slowly introduce the luminescent material solution into the PMMA solution. The solution is clear and transparent. Spin-coat (1200rad/min) on a cleaned aluminum alloy or other metal substrate, dry (60℃, 30min), then put it into VOC for response and test the fluorescence spectrum. The results show that when the fluorescent sensor film is placed in an environment containing pyridine vapor, the maximum emission wavelength will quickly show a blue shift phenomenon (the new maximum emission wavelength is 527nm), and the emission changes from the original green to blue-green, so it can be used as a sensor film for detecting pyridine VOC; in addition, when the fluorescent sensor film is placed in an environment containing cyclohexylamine vapor, it will quickly show a significant fluorescence quenching response effect, and the fluorescent sensor film does not show obvious fluorescence response behavior to many VOC vapors such as triethylamine, trimethylamine, ethanolamine, monomethylamine, 2-phenylpyridine, 3-phenylpyridine, diethylenetriamine, diisopropylamine, and ammonia, so it can also be used as a selective fluorescent sensor film for detecting cyclohexylamine VOC. (See Figures 12, 13, 14, 15, and 16).

Claims (6)

1. A binuclear cuprous cluster luminescent material compounded by nitrogen/phosphine ligands is characterized in that: the binuclear cuprous cluster luminescent material has a structural formula of (Xantphos) Cu ₂I₂(3-PhPy)₂, wherein Xantphos is an electrically neutral diphosphine ligand 4, 5-bis (diphenylphosphine) -9, 9-dimethyl xanthene, and 3-PhPy is a nitrogen-containing ligand 3-phenylpyridine; the binuclear cuprous cluster luminescent material is in a triclinic system, the space group of P-1 is provided, and the unit cell parameters are as follows α＝86.946(2)°，β＝77.009(2)°，γ＝86.351(2)°，/>Z=2, d _C＝1.533g/cm³, the crystalline colour of the material being yellow; the material structure is represented as a binuclear neutral complex, two cuprous ions adopt different tetrahedral coordination modes, and a double tetrahedral structure connected by sharing two bridge group iodide ions is formed; one cuprous in the structure adopts a CuI ₂P₂ tetrahedral coordination mode, wherein two I are bridge iodide ions, and two P come from a biphosphine ligand Xantphos; the other cuprous in the structure adopts a CuI ₂N₂ tetrahedral coordination mode, wherein two I are bridge iodide ions, and two N are respectively from two nitrogen-containing ligands 3-PhPy; and there is stronger supermolecular action between adjacent molecules, wherein one is that two biphosphine ligands in the adjacent molecules form stronger intermolecular pi.pi.stacking action through benzene rings through C-H.pi.interaction between benzene rings and xanthene ring components, and the other is that two 3-PhPy ligands in the adjacent molecules form stronger intermolecular pi.pi.pi.stacking action through benzene rings, and the structural rigidity of the interior of the material is improved; the molecular structure is shown as formula (I):

The binuclear cuprous cluster luminescent material is characterized in that the luminescent material is a broad spectrum excitation high-efficiency luminescent fluorescent powder, emits strong green fluorescence under the excitation of ultraviolet light and visible light within the wavelength range of 250 to 450 nanometers, has the maximum luminescent wavelength of 540nm and the color coordinate value of 0.3899,0.5280, and can be used as a photoluminescence green material or a luminescent layer green material in an electroluminescent device formed by multiple layers of organic materials.

2. The preparation method of the binuclear cuprous cluster light-emitting material according to claim 1, which comprises the following steps:

(1) Weighing CuI powder and powder of ligand Xantphos and 3-PhPy at room temperature, and adding into a ball milling tank;

(2) Adding ball grinding balls into a ball milling tank, wherein the ball-material ratio is 70:1, and then adding 2mL of acetonitrile;

(3) Putting the ball milling tank into a ball mill, setting the rotating speed of the ball mill to 160 revolutions per minute, and performing ball milling treatment for 4 hours;

(4) After ball milling, placing the ball milling tank in a vacuum oven for drying at 40 ℃, and obtaining crystalline powder which is a product;

(5) The molar ratio of the three reactants CuI to Xantphos is 3-PhPy and is 1:2:2, and the ball milling tank is an agate tank with the volume of 50 mL.

3. The fluorescence sensing application of a binuclear cuprous cluster luminescent material according to claim 1, wherein: after the luminescent material (Xantphos) Cu ₂I₂(3-PhPy)₂ is placed in an environment containing pyridine vapor, the luminescent material can rapidly show the luminescent effect of color change and intensity change, and the maximum luminescent wavelength of the luminescent material is blue-shifted, so that the luminescent material can be used as a sensing material for detecting pyridine VOC.

4. The application of the fluorescent sensing film of the binuclear cuprous cluster luminescent material compounded by the nitrogen/phosphine ligand is characterized in that: the fluorescent sensing film is prepared by dissolving binuclear cuprous cluster luminescent material (Xantphos) Cu ₂I₂(3-PhPy)₂ and then coating the dissolved Cu ₂I₂(3-PhPy)₂ on test paper base paper, or dissolving and embedding the dissolved Cu ₂I₂(3-PhPy)₂ in polymer solution and then coating a film on a substrate such as quartz; after the fluorescent sensing film is placed in an environment containing pyridine vapor, the fluorescent sensing film can rapidly show a luminous effect that the color is firstly reduced and then increased, the maximum luminous wavelength of the fluorescent sensing film is blue-shifted, and the new maximum luminous wavelength is 510nm, and the luminescence is changed from the original yellowish green to the bluish green, so that the fluorescent sensing film can be used as a sensing film for detecting pyridine VOC; in addition, after the fluorescent sensing film is placed in an environment containing cyclohexylamine vapor, the fluorescent sensing film can quickly show a remarkable response effect of fluorescence quenching, and the fluorescent sensing film does not show remarkable fluorescence response behaviors for monomethylamine, ethanolamine, diethanolamine, diisopropylamine, diethylenetriamine, trimethylamine, triethylamine, ammonia water, formaldehyde, 2-phenylpyridine and 3-phenylpyridine VOC vapor, so that the fluorescent sensing film can also be used as a selective fluorescent sensing film for detecting cyclohexylamine VOC; wherein the binuclear cuprous cluster luminescent material has a structural formula of (Xantphos) Cu ₂I₂(3-PhPy)₂, xantphos in the formula is electrically neutral diphosphine ligand 4, 5-bis (diphenylphosphine) -9, 9-dimethyl xanthene, and 3-PhPy is nitrogen-containing ligand 3-phenylpyridine; the binuclear cuprous cluster luminescent material is in a triclinic system, the space group of P-1 is provided, and the unit cell parameters are as follows α＝86.946(2)°，β＝77.009(2)°，γ＝86.351(2)°，/>Z=2, d _C＝1.533g/cm³, the crystalline colour of the material being yellow; the material structure is represented as a binuclear neutral complex, two cuprous ions adopt different tetrahedral coordination modes, and a double tetrahedral structure connected by sharing two bridge group iodide ions is formed; the molecular structure is shown as formula (I):

5. the use according to claim 4, wherein the preparation method of the paper-based fluorescence sensing film of the binuclear cuprous cluster luminescent material compounded by the nitrogen/phosphine-containing ligand comprises the following steps:

(1) Dissolving luminescent material (Xantphos) Cu ₂I₂(3-PhPy)₂ powder in dichloromethane at room temperature;

(2) The cellulose film is manufactured into a shape which is required to be conveniently applied, and the shape is used as test paper base paper;

(3) Coating the luminescent material (Xantphos) Cu ₂I₂(3-PhPy)₂ solution on test paper base paper at room temperature;

(4) And finally, drying the coated test paper under a vacuum condition, and obtaining the paper-based fluorescent sensing film after drying.

6. The use according to claim 4, wherein the preparation method of the polymer-based doped fluorescent sensing film of the binuclear cuprous cluster luminescent material compounded by the nitrogen/phosphine-containing ligand comprises the following steps:

(1) Dissolving PMMA solid in dichloromethane at room temperature;

(2) Dissolving luminescent material (Xantphos) Cu ₂I₂(3-PhPy)₂ powder in dichloromethane at room temperature;

(3) Mixing the two solutions, and stirring to fully react to obtain a clear solution A;

(4) And spin-coating the clear solution A on a quartz plate, a metal substrate or a base such as test paper base paper at room temperature, and drying to obtain the doped fluorescent sensing film.