Novel hybrid cuprous iodide luminescent material and preparation method and fluorescent application thereof

Abstract

The application provides a novel hybrid cuprous iodide light-emitting material and a preparation method and fluorescent application thereof, and particularly relates to two light-emitting materials, and both are organic-inorganic hybrids of organic ligands and inorganic cuprous iodide clusters, wherein Cu4I4(C9H 12 N3)2 is a two-dimensional double-layer network structure, the optimal excitation wavelength is 367 nm, and the strongest emission peak is at 602 nm; and Cu2I2(BrC 11 H8N) is a one-dimensional chain structure of ladder-shaped grid structure, the optimal excitation wavelength is 419 nm, and the strongest emission peak is at 521 nm. The light-emitting material is prepared through a diffusion process. The light-emitting material has good fluorescent emission performance, is a novel fluorescent crystal material with potential application value, and can be applied to the fields of solid-state lighting, light-emitting diodes, lasers and fluorescent powder.

Description

Technical Field

[0001] This invention belongs to the technical field of luminescent materials, and relates to a novel hybrid cuprous iodide luminescent material, its preparation method and fluorescence application. Specifically, it discloses at least two novel organic-inorganic hybrid cuprous iodide luminescent materials and their preparation methods. Background Technology

[0002] Organic-inorganic hybrid cuprous iodide materials have occupied an important position in the field of luminescent materials research in recent years and are often regarded as candidate materials for next-generation lighting technologies. In addition to luminescent properties, hybrid cuprous iodide exhibits many additional properties, such as porosity, conductivity, and catalytic activity. Furthermore, the high natural abundance, low toxicity, and low pollution of copper make hybrid cuprous iodide materials economically viable and environmentally friendly. This series of materials possesses unique luminescent characteristics, including outstanding luminescent performance, a variety of emission colors, and optical tunability. In particular, thanks to the excellent coordination chemistry of monovalent copper ions, they can coordinate with many atoms such as C, N, O, P, As, S, and Se. Therefore, Cu… + It can form crystals with different configurations by coordinating with a wide variety of ligands in different coordination modes. This results in an extremely rich structural diversity in the system.

[0003] Since the discovery of the first hybrid cuprous iodide material in the 1970s, thousands of such materials have been reported in the Cambridge Crystal Database. These thousands of crystalline materials can be summarized into three different structural types: (i) both the inorganic cuprous iodide clusters and the organic ligands are electrically neutral and connected by coordinate bonds; (ii) the negatively charged cuprous iodide clusters and the positively charged organic ligands do not form coordinate bonds, but instead form crystals through electrostatic Coulomb forces; and (iii) the negatively charged inorganic cuprous iodide clusters and the positively charged organic ligands are connected by coordinate and ionic bonds. Within the i-type structure, the zero-dimensional structure mainly includes various basic inorganic cluster configurations such as Cu₂I₂-Cu₈I₈, including Cu₂I₂ rhombic dimers, Cu₄I₄ cubane-type tetramers, Cu₆I₆ step-like hexamers, Cu₇I₇ windmill-shaped heptamers, Cu₈I₈ step-like octamers, and Cu₈I₈ dicubane-type octamers. Within the inorganic clusters, Cu… + All are tri- or tetra-coordinated, forming triangular or cubic coordination geometries. Inorganic clusters can further form higher-dimensional crystal structures through organic ligands. Type i configurations also include different types of one-dimensional chain-like and two-dimensional layered inorganic clusters.

[0004] Existing technologies disclose several hybrid cuprous iodide crystal materials. For example, CN114835747B discloses a binuclear cuprous iodide complex luminescent material and its preparation method, as well as the application of this material in fluorescence sensing of pyridine; its luminescent material structure is (m-To l3 The formula is P)2CuI2Cu(m-Tol3P), where m-Tol3P is an electrically neutral phosphine ligand tris(m-methylphenyl)phosphine; it is prepared by a coordination reaction between CuI and the ligand. CN104893715B discloses a yellow-green phosphorescent Cu4I4-type cuboethane cluster core luminescent material and its preparation method. The provided phosphorescent complex is obtained by complexing cuprous iodide with a P-containing ligand, and its molecular structure is Cu4I4(m-anisyl3P)4, where m-anisyl3P is an electrically neutral P-containing ligand tris(m-methoxyphenyl)phosphine. CN109311913A discloses a highly thermally and photo-stable inorganic-organic mixed phosphor compound, wherein a cuprous halide (I) module is coordinated with a multidentate organic ligand; it also discloses semiconductors and light-emitting devices containing these materials, including light-emitting diodes, and methods for preparing these materials and devices.

[0005] However, it remains challenging to further expand the variety of novel hybrid cuprous iodide materials and to provide new design strategies through a deeper understanding of the corresponding material architecture and properties. Summary of the Invention

[0006] This invention leverages the rich structural diversity, excellent luminescent properties, and stability of organic-inorganic hybrid cuprous iodide. Two novel hybrid cuprous iodide materials are obtained by coordinating the organic ligands 1-(4-pyridyl)piperazine with Cu4I4 clusters and 2-(4-bromophenyl)pyridine with Cu2I2 clusters. The prepared luminescent materials exhibit good fluorescence emission properties and are novel fluorescent crystal materials with potential applications in solid-state lighting, light-emitting diodes, lasers, and phosphors, especially for orange and green fluorescence output under ultraviolet light excitation.

[0007] This invention is achieved through the following technical solution:

[0008] On one hand, the present invention provides a novel hybrid cuprous iodide luminescent material, wherein the molecular structural formula of the luminescent material is Cu4I4(1-(4-pyridinyl)piperazine)2, and the chemical formula is Cu4I4(C9H 12 N3)2, 1-(4-pyridinyl)piperazine is 1-(4-pyridinyl)piperazine. Further, the luminescent material Cu4I4(1-(4-pyridinyl)piperazine)2 has a two-dimensional double-layer network structure.

[0009] Furthermore, the Cu4I4(1-(4-pyridinyl)piperazine)2 is a monoclinic crystal system. P 2 / c Space group, cell parameters are a = 9.4684(6) Å, b = 9.9344(6) Å, c = 14.5837(11) Å, α = 90°, β = 97.758(2)°, γ = 90°, unit cell volume V = 1359.23(16) Å 3 .

[0010] The luminescent material Cu₄I₄(1-(4-pyridinyl)piperazine)₂ contains two crystallographically independent Cu atoms in each minimum asymmetric unit cell. + Two I's ‒ One 1-(4-pyridyl)piperazine organic ligand. Four Cu + With four I ‒ This formed cubic Cu4I4 clusters resembling cubane, with each 1-(4-pyridyl)piperazine ligand attaching to two Cu atoms on two Cu4I4 clusters respectively. + Coordination. Each Cu4I4 cluster is coordinated with four 1-(4-pyridyl)piperazines, which are arranged alternately in an alternating manner to form a two-dimensional bilayer network structure.

[0011] On one hand, this invention provides a novel hybrid cuprous iodide luminescent material with the molecular structural formula Cu₂I₂(2-(4-bromophenyl)pyridine) and the chemical formula Cu₂I₂(BrC 11 H8N), 2-(4-bromophenyl)pyridine is 2-(4-bromophenyl)pyridine. Further, the luminescent material Cu2I2(2-(4-bromophenyl)pyridine) has a one-dimensional chain structure.

[0012] Furthermore, the Cu2I2 (2-(4-bromophenyl)pyridine) is a monoclinic crystal system. P twenty one / n Space group, cell parameters are a = 4.210(2) Å, b = 18.705(10) Å, c = 17.825(11) Å,α = 90°, β = 93.184(17)°, γ = 90°, unit cell volume V = 1401.5(14) Å 3 .

[0013] Each minimal asymmetric unit of the luminescent material Cu2I2 (2-(4-bromophenyl)pyridine) contains two crystallographically independent Cu atoms. + Two I's ‒ A 2-(4-bromophenyl)pyridine organic ligand. Cu + with I ‒ A ladder-like inorganic network cluster was formed at a 1:1 ratio, with the 2-(4-bromophenyl)pyridine ligand and a Cu... + Coordination forms a one-dimensional chain structure.

[0014] On the one hand, the present invention provides a method for preparing a novel hybrid cuprous iodide luminescent material, which adopts a layered preparation method, in which organic ligands and inorganic cuprous iodide powder are dissolved in two different solvents, and then a mixed solvent is added to act as an intermediate buffer layer, and the target product is obtained by slow diffusion.

[0015] On the one hand, the present invention provides a method for preparing a novel hybrid cuprous iodide luminescent material, comprising the following steps: placing a cuprous iodide solution as the bottom solution, an aqueous solution as the buffer layer solution, and an organic ligand solution as the top solution in a reaction vessel in sequence, sealing the vessel and allowing it to stand for reaction, and after the reaction is completed, removing the crystals, and obtaining the luminescent material by washing and drying.

[0016] Furthermore, the preparation process of the cuprous iodide solution is as follows: dissolve excess potassium iodide in deionized water, filter to obtain a saturated potassium iodide aqueous solution, and dissolve the cuprous iodide under ultrasonication to obtain a cuprous iodide solution.

[0017] Furthermore, the preparation process of the aqueous solution is as follows: deionized water and organic solvent are mixed.

[0018] Furthermore, the preparation process of the organic ligand solution is as follows: the organic ligand is dissolved in an organic solvent to obtain the solution.

[0019] Furthermore, the present invention provides a method for preparing a novel hybrid cuprous iodide luminescent material, comprising the following steps:

[0020] S1: Dissolve excess potassium iodide in deionized water, filter to obtain a saturated potassium iodide aqueous solution, and dissolve cuprous iodide under sonication to obtain a cuprous iodide solution.

[0021] S2: Prepare an aqueous solution by mixing deionized water and an organic solvent;

[0022] S3: Dissolve the organic ligand in an organic solvent to prepare an organic ligand solution;

[0023] S4: Cuprous iodide solution as the bottom solution, aqueous solution as the buffer layer solution, and organic ligand solution as the top solution are placed in the reaction vessel in sequence, sealed, and allowed to stand for reaction. After the reaction is completed, the crystals are taken out, cleaned, and dried to obtain the luminescent material.

[0024] The preparation method of this invention is simple. A product with high purity can be obtained by standing under normal temperature and pressure conditions. The method is simple and the conditions are convenient, which is conducive to large-scale production and easy to promote on a large scale.

[0025] Furthermore, the molar ratio of the organic ligand to cuprous iodide is 1:1 to 3, preferably 1:1, 1:2, 1:3, etc.

[0026] Furthermore, the organic ligand is selected from at least one of 2-(4-bromophenyl)pyridine and 1-(4-pyridyl)piperazine.

[0027] Furthermore, each of the organic solvents is independently selected from at least one of i-PrOH, EtOH, MeOH, TFE, HFIP, DCM, hexane, THF, toluene, or benzene.

[0028] Furthermore, in S2, the volume ratio of the deionized water to the organic solvent is 1:1.

[0029] Furthermore, the buffer layer solution is slowly dripped onto the surface of the bottom solution.

[0030] Furthermore, the top layer solution is slowly dripped onto the surface of the buffer layer solution.

[0031] On the one hand, the present invention provides the application of a novel hybrid cuprous iodide luminescent material in the preparation of solid-state lighting materials (e.g., residential lighting), light-emitting devices (e.g., light-emitting diodes), security and anti-counterfeiting materials (e.g., tracer tags and anti-counterfeiting), lasers, and phosphors.

[0032] Beneficial effects:

[0033] This invention utilizes the rich structural diversity, excellent luminescent properties, and stability of organic-inorganic hybrid cuprous iodide. A novel hybrid cuprous iodide material, Cu4I4(1-(4-pyridinyl)piperazine)2, is obtained by coordinating a specially structured organic ligand, 1-(4-pyridinyl)piperazine, with Cu4I4 clusters. This luminescent material exhibits a two-dimensional bilayer network structure, with an optimal excitation wavelength of 367 nm and a strongest emission peak at 602 nm, demonstrating good orange fluorescence emission performance. It is a novel fluorescent crystal material with potential applications in solid-state lighting, light-emitting diodes, lasers, and phosphors, particularly for orange fluorescence output under ultraviolet light source excitation.

[0034] This invention utilizes the rich structural diversity, excellent luminescent properties, and stability of organic-inorganic hybrid cuprous iodide. It selects the organic ligand 2-(4-bromophenyl)pyridine with a special structure to coordinate with Cu₂I₂ clusters, thereby obtaining a novel hybrid cuprous iodide material, Cu₂I₂(2-(4-bromophenyl)pyridine). This luminescent material, Cu₂I₂(2-(4-bromophenyl)pyridine), has a one-dimensional chain structure with a ladder-like network, an optimal excitation wavelength of 419 nm, and a strongest emission peak at 521 nm, exhibiting good green fluorescence emission performance. It also demonstrates good fluorescence emission performance, making it a novel fluorescent crystal material with potential applications in solid-state lighting, light-emitting diodes, lasers, and phosphors, especially for green fluorescence output under ultraviolet light source excitation.

[0035] The luminescent materials prepared in this invention exhibit novel crystal structures: Cu4I4(1-(4-pyridinyl)piperazine)2 forms a two-dimensional bilayer network structure, while Cu2I2(2-(4-bromophenyl)pyridine) forms a one-dimensional chain structure with a ladder-like network structure. In particular, the one-dimensional chain structure with the ladder-like inorganic network structure represents a novel inorganic cuprous iodide framework structure, unlike any previously reported type. This significantly broadens the scope of hybrid cuprous iodide materials and expands the range of material types. All luminescent materials prepared in this invention are organic-inorganic hybrids with organic ligands coordinated to inorganic cuprous iodide clusters.

[0036] The preparation method of this invention has advantages such as simple process, low raw material cost, mild reaction conditions, high product yield, high purity, and large crystal size; the required instruments and equipment are simple and easy to operate; the required solvent consumption is low, saving costs and facilitating large-scale technology promotion. This luminescent material can be used to manufacture light-emitting devices and applied in fields such as phosphors and security anti-counterfeiting. Attached Figure Description

[0037] Figure 1 The sample prepared for Example 1 of the present invention is along the crystal axis a A schematic diagram of the crystal structure with different orientations (hydrogen atoms omitted).

[0038] Figure 2 The sample prepared for Example 1 of the present invention is along the crystal axis c A schematic diagram of the crystal structure with different orientations (hydrogen atoms omitted).

[0039] Figure 3 The excitation and emission spectra of the sample prepared in Example 2 of the present invention.

[0040] Figure 4 The sample prepared for Example 2 of the present invention is along the crystal axis a A schematic diagram of the crystal structure with different orientations (hydrogen atoms omitted).

[0041] Figure 5 The sample prepared for Example 2 of the present invention is along the crystal axis b A schematic diagram of the crystal structure with different orientations (hydrogen atoms omitted).

[0042] Figure 6 The excitation and emission spectra of the sample prepared in Example 2 of the present invention. Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0044] The test materials used in the embodiments of the present invention, unless otherwise specified, are all conventional test materials in the art and can be purchased through commercial channels.

[0045] Example 1

[0046] The chemical composition of this embodiment is Cu4I4(C9H) 12 The preparation method of the N3)2 hybrid cuprous iodide luminescent material is as follows:

[0047] First, excess potassium iodide powder is dissolved in a certain amount of deionized water under stirring, and then filtered to obtain a saturated potassium iodide aqueous solution. Then, according to the stoichiometric ratio, high-purity cuprous iodide and 1-(4-pyridyl)piperazine powder are weighed separately, and deionized water, saturated potassium iodide aqueous solution and ethanol solution are measured.

[0048] Dissolve 1 mmol of cuprous iodide powder in 3 mL of saturated potassium iodide aqueous solution by sonication and place it at the bottom of a glass test tube; mix 0.5 mL of deionized water and 0.5 mL of ethanol evenly and place it on top of the cuprous iodide solution; then dissolve 0.5 mmol of 1-(4-pyridyl)piperazine powder in 3 mL of ethanol solution by stirring and place it on top of the mixture of deionized water and ethanol.

[0049] Finally, the test tube was sealed with sealing film and allowed to stand at room temperature for one week to grow crystals. The resulting crystals were removed from the mother liquor, washed with ethanol, and dried to obtain Cu4I4(C9H)2O3. 12 N3)2 crystals (yield 100%).

[0050] The Cu4I4(C9H) prepared in this embodiment 12 A schematic diagram of the crystal structure of N3)2 is shown below. Figure 1 and Figure 2 As shown, the excitation and emission spectra are as follows: the excitation wavelength range is 300-400 nm, with one excitation peak at 375 nm, and the emission peak is located at 602 nm. This indicates that this hybrid cuprous iodide luminescent material can emit orange light.

[0051] Table 1. Novel hybrid cuprous iodide crystal material Cu4I4(C9H) of this invention 12 Crystallographic data of N3)2

[0052]

[0053] Example 2

[0054] The chemical composition of this embodiment is Cu2I2(BrC) 11 The preparation method of the H8N) hybrid cuprous iodide luminescent material is as follows:

[0055] First, excess potassium iodide powder is dissolved in a certain amount of deionized water under stirring, and then filtered to obtain a saturated potassium iodide aqueous solution. Then, the ingredients are prepared according to the stoichiometric ratio, and high-purity cuprous iodide and 2-(4-bromophenyl)pyridine powder are weighed separately, and deionized water, saturated potassium iodide aqueous solution and ethanol solution are measured.

[0056] Dissolve 1 mmol of cuprous iodide powder in 3 mL of saturated potassium iodide aqueous solution by sonication and place it at the bottom of a glass test tube; mix 0.5 mL of deionized water and 0.5 mL of ethanol evenly and place it on top of the cuprous iodide solution; then dissolve 0.5 mmol of 2-(4-bromophenyl)pyridine powder in 3 mL of ethanol solution by stirring and place it on top of the mixture of deionized water and ethanol.

[0057] Finally, the test tube was sealed with sealing film and allowed to stand at room temperature for one week to grow crystals. The resulting crystals were removed from the mother liquor, washed with ethanol, and dried to obtain Cu2I2(BrC)2. 11 H8N) crystal. (100% yield)

[0058] The Cu2I2(BrC) prepared in this embodiment 11 A schematic diagram of the structure of H8N crystal is shown below. Figure 4 and Figure 5 As shown, the excitation and emission spectra are as follows: Figure 6 As shown, the excitation wavelength range is 300-460 nm, with one excitation peak at 419 nm and an emission peak at 521 nm. This indicates that this hybrid cuprous iodide luminescent material can emit green light.

[0059] Table 2. Novel hybrid cuprous iodide crystal material Cu2I2(BrC) of this invention 11 Crystallographic data of H8N

[0060]

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel hybrid cuprous iodide luminescent material, characterized in that, The molecular structure of the luminescent material is Cu4I4(1-(4-pyridinyl)piperazine)2 or Cu2I2(2-(4-bromophenyl)pyridine); The luminescent material Cu4I4(1-(4-pyridinyl)piperazine)2 has a two-dimensional double-layer network structure. The luminescent material Cu2I2 (2-(4-bromophenyl)pyridine) has a one-dimensional chain structure; The Cu4I4(1-(4-pyridinyl)piperazine)2 is a monoclinic crystal system. P 2 / c Space group, cell parameters are a =9.4684(6) Å, b = 9.9344(6) Å, c = 14.5837(11) Å, α = 90°, β = 97.758(2)°, γ =90°, unit cell volume V = 1359.23(16) Å 3 ; The four Cu atoms in the luminescent material Cu4I4(1-(4-pyridinyl)piperazine)2 + With four I ‒ This formed cubic Cu4I4 clusters resembling cubane, with each 1-(4-pyridyl)piperazine ligand attaching to two Cu atoms on two Cu4I4 clusters respectively. + Coordination; Each Cu4I4 cluster is coordinated with four 1-(4-pyridyl)piperazines, which are arranged alternately in an alternating manner to form a two-dimensional bilayer network structure; The Cu2I2 (2-(4-bromophenyl)pyridine) is a monoclinic crystal system. P twenty one / n Space group, cell parameters are a =4.210(2) Å, b = 18.705(10) Å, c = 17.825(11) Å, α = 90°, β = 93.184(17)°, γ =90°, unit cell volume V = 1401.5(14) Å 3 ; The luminescent material Cu2I2(2-(4-bromophenyl)pyridine) contains Cu + with I ‒ A ladder-like inorganic network cluster was formed at a 1:1 ratio, with the 2-(4-bromophenyl)pyridine ligand and a Cu... + Coordination forms a one-dimensional chain structure.

2. A method for preparing the luminescent material according to claim 1, characterized in that, The process includes the following steps: placing cuprous iodide solution as the bottom solution, aqueous solution as the buffer layer solution, and organic ligand solution as the top solution in a reaction vessel in sequence, sealing the vessel, and allowing it to stand for reaction. After the reaction is complete, the crystal is removed, cleaned, and dried to obtain the luminescent material.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the organic ligand to cuprous iodide is 1:1 to 3; The preparation process of the cuprous iodide solution is as follows: Take excess potassium iodide and dissolve it in deionized water, filter to obtain a saturated potassium iodide aqueous solution, and dissolve the cuprous iodide under ultrasonication to obtain a cuprous iodide solution.

4. The preparation method according to claim 2, characterized in that, The organic ligand is selected from at least one of 2-(4-bromophenyl)pyridine and 1-(4-pyridyl)piperazine.

5. The preparation method according to claim 2, characterized in that, The preparation process of the aqueous solution is as follows: deionized water and organic solvent are mixed, wherein the volume ratio of deionized water to organic solvent is 1:1; The preparation process of the organic ligand solution is as follows: Dissolve the organic ligand in an organic solvent to obtain the solution; Each of the organic solvents is independently selected from at least one of i-PrOH, EtOH, MeOH, TFE, HFIP, DCM, hexane, THF, toluene, or benzene; The buffer layer solution is slowly dripped onto the surface of the bottom layer solution; The top layer solution is slowly dripped onto the surface of the buffer layer solution.

6. The use of the luminescent material of claim 1 in the preparation of solid-state lighting materials, light-emitting devices, lasers, and phosphors.

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