Organic near-infrared luminescent material

Abstract

According to the organic near-infrared light-emitting material, a tridentate platinum coordination compound is fused in a boron-containing and oxygen-containing polycyclic aromatic hydrocarbon compound, or the tridentate platinum coordination compound is fused in a boron-containing and nitrogen-containing polycyclic aromatic hydrocarbon compound, so that the organic platinum coordination conjugated light-emitting material with a rigid plane is formed; the compound disclosed by the invention has the outstanding advantages of large light-emitting wavelength and high light-emitting efficiency, and is expected to be applied to the fields of national defense security, electroluminescent devices, anti-counterfeiting marks, optical communication, spectral imaging, disease diagnosis and treatment, night vision and detection and the like.

Description

Technical Field

[0001] This invention relates to the field of organic light-emitting materials technology, and in particular to a class of organic near-infrared light-emitting materials that can be applied in fields such as national defense security, electroluminescent devices, anti-counterfeiting labels, optical communication, spectral imaging, disease diagnosis and treatment, and night vision and detection. Background Technology

[0002] Near-infrared (NIR) light typically refers to electromagnetic waves with wavelengths between 700 and 2500 nm. Compared to visible light, it has better penetrability and is widely used in national defense, electroluminescent devices, anti-counterfeiting, optical communication, spectral imaging, disease diagnosis and treatment, and night vision and detection. Organic optoelectronic materials offer advantages over traditional materials, including tunable molecular structure, lightweight, flexibility, and low cost. However, achieving efficient luminescence in organic NIR materials requires overcoming the energy gap law, which states that a smaller band gap leads to enhanced nonradiative transitions, significantly reducing the fluorescence quantum yield (PLQY). The PLQY of traditional organic NIR materials is generally below 1%. Furthermore, in organic electroluminescence, spin statistical confinement limits fluorescent materials to utilizing only 25% of singlet excitons, as triplet excitons are dissipated through nonradiative decay. Donor-acceptor (DA) structures are a common strategy for generating deep red / near-infrared luminescent materials, offering a wide selection of donor sites but limited choices of strong electron-withdrawing acceptors. Furthermore, the strong charge transfer caused by the donor-acceptor structure significantly increases the full width at half maximum (FWHM) of the emission spectrum, reducing the purity of the emission color. In their paper "Adv. Mater., 2016, 28, 2777–2781," Hatakeyama et al. designed planar boron- and oxygen- (or nitrogen-) aromatic compounds called multi-resonance (MR) luminescent materials. The rigid structure of these molecules significantly reduces molecular vibrations, resulting in a narrower emission spectrum (FWHM < 30 nm). However, the biggest challenge for MR-based luminescent materials is that their emission almost entirely falls within the blue and green light regions, making it difficult to extend the emission wavelength into the red region, and even more difficult to achieve near-infrared emission. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a type of organic near-infrared luminescent material, which achieves a maximum emission wavelength of over 750 nm and a luminescence efficiency of over 0.1 by fusing multiple resonant molecular fragments with platinum metal, far exceeding the efficiency of traditional donor-acceptor (DA) structure near-infrared luminescent materials.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A class of organic near-infrared luminescent materials are formed by fusing tridentate platinum coordination compounds into boron- and oxygen-containing polycyclic aromatic hydrocarbon compounds, or by fusing tridentate platinum coordination compounds into boron- and nitrogen-containing polycyclic aromatic hydrocarbon compounds, to create rigid planar organic platinum coordination conjugated luminescent materials. The general molecular framework formula of these materials is as follows:

[0006]

[0007] In the above formulas (A, B), X1 and X2 each independently include NR, C=O, O, S or Se;

[0008] In the above formulas (A, B), R1, R2, R4, and R5 are substituents. R1, R2, R4, and R5 are attached to any substituted position of the aromatic ring and can simultaneously substitute one or more of all substituted positions of the corresponding aromatic ring.

[0009] In the above formulas (A, B), R3 includes chloro, cyano, isothiocyano, and alkyne derivatives.

[0010] X3 can be any saturated or unsaturated substituent;

[0011] In the above formulas (A, B), N1 and N2 represent aromatic amine derivatives, and N1 and N2 are each independently selected from heterocyclic fused-ring aromatic hydrocarbons obtained by reacting various heteroatom-containing fused-ring aromatic amines with embedded NH groups.

[0012] When NR is present in X1 and X2, R is selected from one of the following groups, substituted or unsubstituted: C1-C10 alkyl groups, C6-C30 monocyclic aromatic hydrocarbons, C6-C30 monocyclic aromatic hydrocarbons, C5-C30 monocyclic heteroaromatic hydrocarbons, and C5-C30 heteroaromatic hydrocarbons.

[0013] R1, R2, R4, and R5 each independently comprise hydrogen, deuterium, fluorine, chlorine, or one of the following groups, substituted or unsubstituted: C1-C20 straight-chain alkyl, substituted or unsubstituted C1-C20 branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, C6-C48 monocyclic aromatic hydrocarbon, C6-C48 fused-ring aromatic hydrocarbon, C3-C48 monocyclic heteroaromatic hydrocarbon, C3-C48 fused-ring heteroaromatic hydrocarbon, C6-C30 arylamino, C3-C30 heteroarylamino, and C1-C36 alkoxy.

[0014] The X3 includes one of the following groups, substituted or unsubstituted: C1-C10 alkyl groups, C6-C30 monocyclic aromatic hydrocarbons, C6-C30 monocyclic aromatic hydrocarbons, C5-C30 monocyclic heteroaromatic hydrocarbons, and C5-C30 heteroaromatic hydrocarbons.

[0015] The N1 and N2 include substituted or unsubstituted carbazolyl derivatives, substituted or unsubstituted acridinel derivatives, substituted or unsubstituted phenoxazinyl derivatives, substituted or unsubstituted phenothiazinyl derivatives, substituted or unsubstituted phenselenazinyl derivatives, substituted or unsubstituted azacarbazolyl derivatives, and substituted or unsubstituted carbazo[a]-fused-ring aromatic derivatives.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The innovation of this invention lies in the fact that by incorporating a tridentate platinum coordination compound into a boron-containing and oxygen-containing (or nitrogen-containing, etc.) polycyclic aromatic hydrocarbon compound, the highest occupied molecular orbital energy level of the material can be greatly reduced, thereby significantly reducing the excited state energy and realizing near-infrared luminescence.

[0018] 2. These molecules form a rigid planar structure, which can significantly suppress the deformation and vibration of excited-state molecules, thereby reducing non-radiative transitions, improving near-infrared luminescence efficiency, and overcoming the adverse effects of the bandgap law on organic light-emitting materials.

[0019] In summary, this invention fuses a tridentate platinum coordination compound into boron-containing and oxygen-containing (or nitrogen-containing, etc.) polycyclic aromatic hydrocarbon compounds to form a rigid planar structure. The combined effect of these two components ultimately achieves high luminous efficiency and long-wavelength pure near-infrared emission. These advantages significantly enhance its performance in applications such as national defense security, electroluminescent devices, anti-counterfeiting labels, optical communication, spectral imaging, disease diagnosis and treatment, and night vision and detection. Attached Figure Description

[0020] Figure 1 This is the main synthetic route diagram for synthesizing organic near-infrared luminescent materials according to the present invention.

[0021] Figure 2 This is the spatial structure of Pt5, the representative molecule of the organic near-infrared luminescent material synthesized in this invention; wherein, Figure 2 (a) in the figure is the front view. Figure 2 (b) in the image is a side view.

[0022] Figure 3 This is the mass spectrum of the product of Example 8 of the present invention. Detailed Implementation

[0023] The specific preparation method of the above-mentioned organic near-infrared luminescent material of the present invention is described in detail below with reference to the accompanying drawings and multiple synthetic embodiments. However, the preparation method of the present invention is not limited to these synthetic embodiments.

[0024] It should be noted that, unless otherwise defined below, all technical and scientific terms used herein are intended to have the same meaning as commonly understood by those skilled in the art. References to technical terms herein refer to techniques commonly understood in the art, including variations or equivalent substitutions of techniques that are obvious to those skilled in the art. While it is believed that the following terms will be well understood by those skilled in the art, the following definitions are set forth to better explain the invention.

[0025] In this specification, the expressions Ca to Cb indicate that the group has a to b carbon atoms. Unless otherwise specified, this number of carbon atoms generally does not include the number of carbon atoms in the substituents. When describing C1 to C30, this includes, but is not limited to, C1, C2, C3, C4, C3, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C24, C26, and C28. Other numerical ranges are not elaborated. The terms "comprising," "including," "having," "containing," or "involving," and their other variations herein, are inclusive or open-ended and do not exclude other unlisted elements or method steps. In this invention, unless otherwise specified, the description of chemical elements generally includes the concept of isotopes with the same chemical properties. For example, the description of "hydrogen" also includes the concepts of "deuterium" and "tritium" with the same chemical properties, and carbon (C) includes... 12 C 13C, etc., will not be elaborated further. Heteroatoms in this invention generally refer to those selected from N, O, S, B, P, Si, and Se. As used herein, the term "heterocyclic group" refers to a saturated (i.e., heterocyclic alkyl) or partially unsaturated (i.e., having one or more double and / or triple bonds within the ring) cyclic group having at least one ring atom selected from N, O, and S and the remaining ring atoms being C. If a substituent is described as "independently selected" from a group, each substituent is chosen independently of the others. Therefore, each substituent may be the same as or different from another (other) substituent. Unless otherwise specified, as used herein, the connection point of a substituent may originate from any suitable position of the substituent. When the bond of a substituent is shown as a bond connecting two atoms through the ring, such a substituent may be bonded to any cyclic atom in the substituted ring. Unless otherwise specified, the C6-C60 aromatic rings and C3-C60 heteroaromatic rings mentioned above in this invention refer to aromatic groups that satisfy the π-conjugated system, including both monocyclic residues and fused-ring residues. A monocyclic residue refers to a molecule containing at least one phenyl group. When a molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by single bonds. A fused-ring residue refers to a molecule containing at least two benzene rings or five- or six-membered conjugated heterocycles, but the benzene rings or five- or six-membered conjugated heterocycles are not independent of each other, but rather fused together by sharing ring edges. A five- or six-membered conjugated heterocycle refers to a molecule containing at least one heteroaryl group. When a molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by single bonds. A fused-ring heteroaryl group refers to a molecule formed by the fusion of at least one phenyl group and at least one heteroaryl group, or by the fusion of at least two heteroaromatic rings.

[0026] like Figure 1 The present invention discloses a class of organic near-infrared luminescent materials, which are formed by fusing a tridentate platinum coordination compound into a boron- and oxygen-containing polycyclic aromatic hydrocarbon compound, or by fusing a tridentate platinum coordination compound into a boron- and nitrogen-containing polycyclic aromatic hydrocarbon compound, to form a rigid planar organic platinum coordination conjugated luminescent material A or B. The core feature is that heterocyclic aromatic hydrocarbons containing atoms such as B, N, S, and O form tridentate ligands, which coordinate with platinum to form organic platinum complex compounds.

[0027] Example 1

[0028]

[0029] The organic ligand OCz-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The product was then purified by silica gel column chromatography to obtain the dark brown solid target product Pt1, with an MS (m / z) of 894.28 [M]. + .

[0030] Example 2

[0031]

[0032] The organic ligand DPACz-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The target product, Pt2, was obtained as a black solid by silica gel column chromatography, with an MS (m / z) of 1025.39 [M]. + .

[0033] Example 3

[0034]

[0035] The organic ligand DPACzNF-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The target product, Pt3, was obtained as a black solid by silica gel column chromatography, with an MS (m / z) of 986.30 [M]. + .

[0036] Example 4

[0037]

[0038] The organic ligand SOCz-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The target product, Pt4, was obtained as a black solid by silica gel column chromatography, with an MS (m / z) of 919.15 [M]. + .

[0039] Example 5

[0040]

[0041] The organic ligand NCzSO-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The target product, Pt5, was obtained as a brownish-black solid by silica gel column chromatography, with the structure shown below. Figure 2 As shown, the molecule forms a rigid structure with a fully fused ring configuration, and its MS (m / z) is 864.08 [M]. + .

[0042] Example 6

[0043]

[0044] The product Pt5 and aryl alkyne were added to a reactor at a molar ratio of approximately 1:2. Approximately one-times the amount of KOH and 50 mL of methanol were added to the reaction vessel. The mixture was heated to reflux under a nitrogen atmosphere and reacted for approximately 12-24 hours. After the reaction was complete, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The product was then purified by silica gel column chromatography to obtain the black solid target product Pt6, with an MS (m / z) of 973.20 [M]. + .

[0045] Example 7

[0046]

[0047] The product Pt1 and aryl alkyne were added to a reactor at a molar ratio of approximately 1:2. Approximately one-times the amount of KOH and 50 mL of methanol were added to the reaction vessel. The mixture was heated to reflux under a nitrogen atmosphere and reacted for approximately 12-24 hours. After the reaction was complete, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The product was then purified by silica gel column chromatography to obtain the black solid target product Pt7, with an MS (m / z) of 1068.36 [M]. + .

[0048] Example 8

[0049]

[0050] The organic ligand DPACzNCl-L and divalent platinum salt were added to a reactor at a molar ratio of approximately 1:1. 50 mL of acetic acid was added to the reaction vessel, and the mixture was heated to reflux under a nitrogen atmosphere for approximately 36-48 hours. After the reaction, the mixture was poured into a large amount of deionized water to precipitate the crude product. The crude product was filtered, extracted with dichloromethane, and the dichloromethane was removed by vacuum distillation. The target product, Pt8, was obtained by silica gel column chromatography, and its mass spectrum is shown below. Figure 3 Its MS (m / z) is 1058.35 [M]. + .

[0051] The emission wavelengths and mass spectrometry data of the representative compounds prepared in the above-described synthetic examples of the present invention are shown in the table below.

[0052] Example number Compound numbering Maximum emission wavelength Mass-to-charge ratio MS (m / z) Example 1 Pt1 767nm 986.30[M]+ Example 2 Pt2 835nm 1025.39[M]+ Example 3 Pt3 818nm 986.30[M]+ Example 4 Pt4 776nm 919.15[M]+ Example 5 Pt5 752nm 864.08[M]+ Example 6 Pt6 769nm 973.20[M]+ Example 7 Pt7 782nm 1068.36[M]+ Example 8 Pt8 852nm 1058.35[M]+

[0053] The above data demonstrates that the compounds involved in this invention possess significant near-infrared luminescence capabilities, and their emission wavelengths are much larger than those of traditional MR luminescent molecules (almost all concentrated below 550 nm), indicating that this invention represents a significant innovation in the development of organic near-infrared luminescent materials. The specific embodiments of this invention have been described above in conjunction with the accompanying drawings, but these descriptions should not be construed as limiting the scope of the invention. The scope of protection of this invention is defined by the appended claims, and any modifications based on the claims of this invention are within the scope of protection of this invention.

Claims

1. A class of organic near-infrared luminescent materials, characterized in that, By fusing tridentate platinum coordination compounds into boron- and oxygen-containing polycyclic aromatic hydrocarbons, or by fusing tridentate platinum coordination compounds into boron- and nitrogen-containing polycyclic aromatic hydrocarbons, rigid planar organic platinum coordination conjugated luminescent materials are formed, with the following general molecular framework formula: In equations (A, B), X1 and X2 each independently include NR, C=O, O, S or Se; In the above formulas (A, B), R1, R2, R4, and R5 are substituents. R1, R2, R4, and R5 are attached to any substituted position of the aromatic ring and can simultaneously substitute one or more of all substituted positions of the corresponding aromatic ring. In the above formulas (A, B), R3 includes chloro, cyano, isothiocyano, and alkyne derivatives. X3 can be any saturated or unsaturated substituent; In the above formulas (A, B), N1 and N2 represent aromatic amine derivatives, and N1 and N2 are each independently selected from heterocyclic fused-ring aromatic hydrocarbons obtained by reacting various heteroatom-containing fused-ring aromatic amines with embedded NH groups.

2. The organic near-infrared luminescent material according to claim 1, characterized in that, When NR is present in X1 and X2, R is selected from one of the following groups, substituted or unsubstituted: C1-C10 alkyl groups, C6-C30 monocyclic aromatic hydrocarbons, C6-C30 monocyclic aromatic hydrocarbons, C5-C30 monocyclic heteroaromatic hydrocarbons, and C5-C30 heteroaromatic hydrocarbons.

3. The organic near-infrared luminescent material according to claim 1, characterized in that, R1, R2, R4, and R5 each independently comprise hydrogen, deuterium, fluorine, chlorine, or one of the following groups, substituted or unsubstituted: C1-C20 straight-chain alkyl, substituted or unsubstituted C1-C20 branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, C6-C48 monocyclic aromatic hydrocarbon, C6-C48 fused-ring aromatic hydrocarbon, C3-C48 monocyclic heteroaromatic hydrocarbon, C3-C48 fused-ring heteroaromatic hydrocarbon, C6-C30 arylamino, C3-C30 heteroarylamino, and C1-C36 alkoxy.

4. The organic near-infrared luminescent material according to claim 1, characterized in that, The X3 includes one of the following groups, substituted or unsubstituted: C1-C10 alkyl groups, C6-C30 monocyclic aromatic hydrocarbons, C6-C30 monocyclic aromatic hydrocarbons, C5-C30 monocyclic heteroaromatic hydrocarbons, and C5-C30 heteroaromatic hydrocarbons.

5. The organic near-infrared luminescent material according to claim 1, characterized in that, The N1 and N2 include substituted or unsubstituted carbazolyl derivatives, substituted or unsubstituted acridinel derivatives, substituted or unsubstituted phenoxazinyl derivatives, substituted or unsubstituted phenothiazinyl derivatives, substituted or unsubstituted phenselenazinyl derivatives, substituted or unsubstituted azacarbazolyl derivatives, and substituted or unsubstituted carbazo[a]-fused-ring aromatic derivatives.

Images