High-contrast circularly polarized luminescent composite material and preparation method and application thereof

Abstract

The present invention discloses a high-contrast circularly polarized luminescent composite material and its preparation method and application, which belongs to the cross-field of coordination chemistry and chiral science. The chiral complex composite material is a chiral gold (I) complex. R / S ‑(4‑bromo‑phenylethylisocyanato)gold(cyano) is the main molecular crystal, into which a certain proportion of another non-luminescent gold(I) complex is doped by a solution method. R / S ‑(4‑bromo‑phenylethylisocyanato)gold(iodine), thereby obtaining a chiral composite material with dual emission, abbreviated as R ‑Au‑CN R ‑Au‑I or S ‑Au‑CN S ‑Au‑I. Among them, the host chiral gold (I) complex S ‑Au‑CN exhibits blue CPL, and the interaction between the host and guest molecules gives the composite material dual emission CPL properties. The composite material exhibits blue CPL under the action of grinding force, and after fumigation with dichloromethane solvent, it exhibits red CPL. The composite material is easy to prepare, and exhibits high-contrast CPL with blue-red switching under external stimulation of grinding / dichloromethane fumigation, making it suitable as a CPL switch material.

Description

Technical Field

[0001] The invention belongs to the intersecting field of coordination chemistry and chiral science, and specifically relates to a chiral coordination compound composite material and a preparation method thereof and application thereof in a high-contrast circularly polarized luminescence (CPL) switch. Background Art

[0002] Circularly polarized luminescent (CPL) materials refer to materials that can emit left-handed or right-handed circularly polarized light. CPL reflects the structural information of chiral luminescent materials in an excited state. In recent years, circularly polarized luminescent materials have attracted much attention from scientists due to their important application prospects in 3D display, chiral optoelectronic devices, chiral recognition, asymmetric catalysis, information storage and transmission. Among them, stimulus-responsive CPL materials have become a new type of intelligent optical materials because they exhibit adjustable CPL performance under external stimuli. CPL switches refer to materials whose luminescence properties (i.e., luminescence wavelength, intensity, and chiral direction) undergo reversible changes under two different external stimuli. Because of its good application prospects in the fields of anti-counterfeiting, information encryption, and sensing, it has been widely studied. However, at present, under different external stimuli, the luminescence wavelength of the CPL switch performance system changes little, and the luminescence color changes are not obvious, which is not conducive to identification and detection, and seriously limits its application in practice. High-contrast CPL switches help improve the security of anti-counterfeiting and information encryption technologies. Therefore, the development of CPL switch materials with high contrast is of great significance, but also challenging.

[0003] Isocyanogen(I) complex materials have unique advantages in achieving stimulus-responsive luminescence performance because their stacking structure is easily transformed under external stimuli. In recent years, isocyanogen(I) complexes with various structures have been designed and synthesized, resulting in many novel stimulus-responsive luminescent materials. When different external stimuli are applied to them, such as scratching, acupuncture, grinding, light, heating / cooling, fumigation of organic volatile molecules, etc., they show different luminescence characteristics and can be used for anti-counterfeiting, information storage and fluorescence sensing.

[0004] In addition to chemical synthesis, two isocyanogens (I) are physically doped in different proportions to produce some new types of photofunctional materials, which have adjustable luminescent properties and better overall performance than a single component. The application of isocyanogen (I) complexes and host-guest chemistry has developed rapidly, opening up new avenues for the development of new photofunctional materials. At present, this research is still in its initial stage and there are many challenges. It is necessary to further explore molecular pairs with better matching chemical structures and physicochemical properties as functional host and guest materials to construct homogeneous composite materials with excellent luminescent properties. Therefore, designing and synthesizing functional host and guest molecular pairs with better matching chemical structures and physicochemical properties is one of the difficulties and key points in the research of the host-guest field. Summary of the invention

[0005] The present invention aims to provide a chiral coordination compound material and a preparation method thereof; another aim is to provide the application of the chiral coordination compound composite material in a CPL switch.

[0006] To achieve the purpose of the present invention, the present invention uses a blue luminescent chiral gold (I) complex R / S-(4-Br-C8H8NC)Au(CN)(R / S-(4-bromo-phenylethyl isocyano)gold (cyano), abbreviated as R / S-Au-CN) as a main lattice material, and dopes a certain proportion of another non-luminescent gold (I) complex R / S-(4-Br-C8H8NC)Au(I)(R / S-(4-bromo-phenylethyl isocyano)gold (iodine), abbreviated as R / S-Au-I) therein, and synthesizes a composite material with high yield and adjustable luminescent color by a simple poor solvent diffusion method. The chemical formula is C 9.97 HkDJ 0.03 N 1.97 , referred to as R-Au-CNR-Au-I or S-Au-CNS-Au-I; S-Au-CNS-Au-I, its single crystal belongs to the monoclinic system, the space group is the chiral space group C2, α=γ=90°, β=97.161(1)°,

[0007] The chiral complex composite material is prepared by the following steps:

[0008] A small amount of guest molecule complex R-Au-I or S-Au-I powder of different masses is added to a test tube containing a dichloromethane solution of a host molecule complex R-Au-CN or S-Au-CN. Subsequently, ultrasound is applied until all the powder is dissolved to form a transparent solution, and then an ether solvent is diffused therein to form needle-shaped crystals to obtain a chiral gold (I) complex composite material, abbreviated as R-Au-CNR-Au-I or S-Au-CNS-Au-I, which is filtered, washed, and dried; the guest molecule complex R / S-Au-I is R / S-(4-bromo-phenylethylisocyano) gold (iodine), and the host molecule complex R / S-Au-CN is R / S-(4-bromo-phenylethylisocyano) gold (cyano).

[0009] The molar ratio of the guest molecule complex to the host molecule complex is in the range of 5:95 to 1:1.

[0010] The chiral complex composite material of the present invention is used for CPL switch, and its properties are specifically described as follows:

[0011] The chiral gold (I) complex composite material has the same crystalline structure as the main molecule R / S-Au-CN crystal (XRD as Figure 1 and 2The introduction of the guest molecule R / S-Au-I did not destroy the main crystal structure of the R / S-Au-CN crystal. Under room temperature conditions, the composite materials of different complexes have different luminescence colors from the main molecule crystal. The fluorescence photos are shown in Figure 3 (excitation wavelength is 365nm), CPL spectrum is as follows Figure 4 As shown; the fluorescence photo and emission spectrum of S-Au-CNS-Au-I powder after grinding and fumigation with dichloromethane solvent are shown Figure 6 and 7 CPL spectra and circular polarization asymmetry factor (g) of R / S-Au-CNR / S-Au-I powders after grinding and fumigation with dichloromethane solvent lum ) Curve such as Figure 8 and 9 shown.

[0012] Beneficial effects of the present invention: The chiral gold (I) complex composite material of the present invention exhibits dual emission peaks under the excitation of a 365nm ultraviolet light source, respectively in the blue light region of 400-500nm and the red light region of 600-800nm. Among them, the blue light emission in the 400-500nm band originates from the host lattice, and the red light emission in the 600-800nm ​​band originates from the interaction between the host and guest molecules. In addition, under the action of grinding force, blue light CPL is exhibited; further, it is placed in a dichloromethane vapor atmosphere for fumigation treatment, and it exhibits red light CPL, which has good application value in CPL switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the XRD diagram of the R-Au-CNR-Au-I composite material of the present invention.

[0014] Figure 2 This is the XRD diagram of the S-Au-CNS-Au-I composite material of the present invention.

[0015] Figure 3 It is the CPL spectrum of the S-Au-CNS-Au-I and R-Au-CNR-Au-I composite materials of the present invention.

[0016] Figure 4 This is a fluorescent photograph of the S-Au-CNS-Au-I composite material of the present invention.

[0017] Figure 5 This is the S-Au-CNS-Au-I crystal stacking structure of the present invention.

[0018] Figure 6 This is a fluorescent photograph of the S-Au-CNS-Au-I composite material of the present invention after grinding and fumigation with dichloromethane solvent.

[0019] Figure 7 The fluorescence spectrum of the S-Au-CNS-Au-I composite material of the present invention after grinding and fumigation with dichloromethane solvent.

[0020] Figure 8 CPL spectra of the S-Au-CNS-Au-I and R-Au-CNR-Au-I composites of the present invention after grinding and fumigation with dichloromethane solvent.

[0021] Fig. 9 is the circularly polarized light asymmetry factor (g lum )curve. DETAILED DESCRIPTION

[0022] The present invention will be further described below by way of examples:

[0023] Example 1: Synthesis of the chiral gold (I) complex composite material (S-Au-CNS-Au-I) of the present invention

[0024] 4.32 mg (0.01 mmol) of S-Au-CN powder was added to the test tube. Subsequently, 0.25 mL of dichloromethane was added to the test tube, and the test tube was shaken vigorously and ultrasonicated to dissolve the crystals. The same volume of dichloromethane solution containing 5.34 mg (0.01 mmol) of S-Au-I was added, the mouth of the test tube was plugged with cotton, and placed in a sealed wide-mouth bottle filled with ether atmosphere. After several hours, needle-shaped crystals were formed without interference. Filter, wash with ether, and dry. Its XRD pattern is shown in Figure 2 Its CPL spectrum is shown in Figure 3 ;

[0025] (1) Crystal structure determination

[0026] The X-ray single crystal diffraction data of the composite material was measured by measuring the single crystal sample of suitable size and good quality on the Rigaku XtaLAB Pro single crystal diffractometer. The data were all measured by Cu Kα radiation monochromatized by graphite. The diffraction source was collected by ω scanning. The structure was first solved by direct method using SHELXS-97 program, and then refined by full matrix least squares method using SHELXL-97 program. All non-hydrogen atoms were refined by anisotropic thermal parameter method. All hydrogen atoms were refined by isotropic thermal parameter method. Detailed crystal determination data are shown in Table 1, and crystal packing diagram is shown in Figure 5 .

[0027] Table 1 Main crystallographic data of the complex composite material of the present invention

[0028]

[0029] Example 2: Synthesis of the chiral gold (I) complex composite material (R-Au-CNR-Au-I) of the present invention

[0030] 4.32 mg (0.01 mmol) of R-Au-CN powder was added to a test tube. Subsequently, 0.25 mL of dichloromethane was added to the test tube, and the test tube was shaken vigorously and ultrasonicated to dissolve the crystals. The same volume of dichloromethane solution containing 5.34 mg (0.01 mmol) of R-Au-I was added, the mouth of the test tube was plugged with cotton, and placed in a sealed wide-mouth bottle filled with ether atmosphere. After several hours, needle-shaped crystals were formed without interference. Filter, wash with ether, and dry. Its XRD pattern is shown in Figure 1 Its CPL spectrum is shown in Figure 3 .

[0031] Example: Chiral gold (I) complex composite materials (S-Au-CN□S-Au-I and R-Au-CN□R-Au-I) of the present invention as CPL switches

[0032] The chiral gold (I) complex composite materials (S-Au-CN□S-Au-I and R-Au-CN□R-Au-I) samples prepared in Examples 1 and 2 were ground into fine solid powders, which were smeared on a quartz plate for further testing. The ultraviolet light excited the material to emit blue CPL (e.g. Figure 8 Then it was placed in a dichloromethane atmosphere for fumigation treatment, and further tested, and ultraviolet light stimulated the material to emit red CPL (as shown in Figure 8 shown).

[0033] The above embodiments are only used to illustrate the content of the present invention. In addition, the present invention has other embodiments. However, all technical solutions formed by equivalent replacement or equivalent deformation methods fall within the protection scope of the present invention.

Claims

1. A two-component chiral gold (I) complex composite material, characterized in that: The chemical formula is C 9.97 HkDJ 0.03 N 1.97 , referred to as R -Au-CN R -Au-I or S -Au-CN S -Au-I; among them, S -Au-CN S -Au-I, its single crystal belongs to the monoclinic system, and its space group is a chiral space group C 2, α = γ = 90°, β = 97.161(1)°, a =26.4764(4) Å, b =12.4326(2) Å, c = 6.8238(1) Å, V = 3138.91(5) Å 3 ; R -Au-I R -(4-bromo-phenylethylisocyanato)gold(iodine), R -Au-CN R -(4-bromo-phenylethylisocyanato)gold(cyano); S -Au-I S -(4-bromo-phenylethylisocyanato)gold(iodine), S -Au-CN S -(4-Bromo-phenylethylisocyanato)gold(cyano) ; said R -Au-CN R -Au-I has characteristic peaks of powder X-ray diffraction as shown in Figure 1.

2. The two-component chiral gold (I) complex composite material according to claim 1, characterized in that: S -Au-CN S -Au-I has characteristic peaks of powder X-ray diffraction as shown in Figure 2.

3. A method for preparing the two-component chiral gold (I) complex composite material as claimed in claim 1 or 2, characterized in that: This is achieved by: R -Au-I or S -Au-I powder is added to the complex containing the main molecule R -Au-CN or S -Au-CN in a dichloromethane solution in a test tube; then, ultrasonicate until the powder is completely dissolved to form a transparent solution, and then diffuse ether solvent into it to precipitate crystals to obtain a chiral gold (I) complex composite material, abbreviated as R -Au-CN R -Au-I or S -Au-CN S -Au-I, filtered, washed, and dried; the guest molecule complex R -Au-I R -(4-bromo-phenylethylisocyanato)gold(iodine), S -Au-I S -(4-bromo-phenylethylisocyanato)gold(iodine); host molecule complex R -Au-CN R -(4-bromo-phenylethylisocyanato)gold(cyano), S -Au-I S -(4-Bromo-phenylethylisocyanato)gold(iodine).

4. The use of the two-component chiral gold (I) complex composite material as claimed in claim 1 or 2, characterized in that: It is applied to circularly polarized light emitting switches.

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