Chiral heptanuclear metal cluster compound and preparation method and application thereof

Abstract

The invention discloses a chiral heptanuclear metal cluster compound as well as a preparation method and application thereof. The chiral heptanuclear metal cluster compound has a structure as shown in a formula I, the chiral heptanuclear metal cluster compound is used as a luminescent material to be applied to illumination and display, and is used as a circular polarization luminescent material to be applied to the fields of three-dimensional display, biosensing, encryption anti-counterfeiting and the like. The chiral heptanuclear metal cluster compound provided by the invention has the advantages of high luminous efficiency, cheap and easily available raw materials, environmental friendliness, simple synthesis method, and very high purity and yield of the obtained product. # imgabs0 #

Description

Technical Field

[0001] The present application relates to a chiral seven-nuclear coin metal cluster and a preparation method and application thereof, belonging to the technical field of coin metal cluster phosphorescent materials and electroluminescent diode applications. Background Art

[0002] Circularly polarized luminescence (CPL) has extremely broad application prospects in the fields of three-dimensional holographic display, augmented reality (AR) and virtual reality (VR), optical data storage, biological imaging, and photonic quantum information processing. Traditional circularly polarized light is usually generated by a combination of a linear polarizer and a quarter-wave plate, but at least 50% of the photons are lost in this process, resulting in significant energy loss. In contrast, circularly polarized light-emitting diodes (CP-OLEDs) made of circularly polarized luminescent materials can directly generate circularly polarized light, and their manufacturing process is simpler and the energy utilization rate is higher. At present, circularly polarized light-emitting diodes (CP-OLEDs) often use chiral organic materials or chiral lanthanide metal complexes as luminescent materials. However, the complex synthesis process and limited efficiency of such materials limit the further development and practical application of CP-OLEDs. Therefore, the development of new circularly polarized luminescent materials with simple synthesis process and high efficiency is of great significance for the practical application of CP-OLEDs.

[0003] Ligand-protected coin metal clusters have the advantages of high luminescence efficiency and good photothermal stability due to their unique organic-inorganic hybrid interface, the interaction between ligands and metals, and the interaction between metals. At the same time, the synthesis process of this type of material is simple. By changing the ligand structure, the luminescence characteristics of the metal core can be adjusted to meet the needs of practical applications. Furthermore, by introducing chiral ligands or inducing chirality in the metal core, this type of material can produce circularly polarized luminescence. Therefore, it is an ideal choice to develop new circularly polarized luminescent materials with simple synthesis processes based on coin metal clusters. Summary of the invention

[0004] The purpose of the present application is to provide a new chiral seven-coin metal cluster luminescent material, a preparation method thereof, and its application in electroluminescent diodes and circularly polarized light-emitting diodes.

[0005] According to the first aspect of the present application, a chiral seven-coin metal cluster is provided, wherein the chiral seven-coin metal cluster has a structure shown in Formula I:

[0006]

[0007] In formula I, the valence state of M is +1;

[0008] M is selected from copper or silver;

[0009] X is selected from ClO4 - PF6 - CF3SO3 - 、BF4 - 、SbF6 - CF3CF2CF2CF2SO3 - One of;

[0010] R is independently selected from one of C1-C20 alkyl, C6-C20 aryl, C5-C20 heteroaryl, C1-C2 substituted alkyl, C6-C20 substituted aryl, and C5-C20 substituted heteroaryl;

[0011] The substituents in the substituted alkyl, substituted aryl, and substituted heteroaryl are independently selected from one of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, amino, halogen, C1-C20 haloalkyl, C6-C20 aryl, and C5-C20 heteroaryl;

[0012] The heteroatom in the heteroaryl group is N.

[0013] Optionally, the R is independently selected from one of C1-C8 alkyl, C6-C12 aryl, C5-C12 heteroaryl, C1-C8 substituted alkyl, C6-C12 substituted aryl, and C5-C12 substituted heteroaryl;

[0014] The substituents in the substituted alkyl, substituted aryl and substituted heteroaryl are independently selected from one of C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 alkoxy, C1-C12 haloalkyl, C6-C12 aryl and C5-C12 heteroaryl.

[0015] Optionally, X represents a monovalent anionic group, X is selected from ClO4 - or BF4 - .

[0016] Optionally, R represents a substituent, which is the same or different and is independently selected from the following groups which are unsubstituted or optionally substituted by one or more Rs: one of C1-C20 alkyl, C3-20 cycloalkyl, C6-C20 aryl, and C5-C20 heteroaryl;

[0017] The Rs is selected from one of C1-C20 alkyl, C3-C20 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, amino, halogen, C1-C20 haloalkyl, C6-C20 aryl, and C5-C20 heteroaryl.

[0018] Optionally, each R is the same or different and is independently selected from one of phenyl, naphthyl, 4-N,N-dimethyl-phenyl, 4-N,N-diphenyl-phenyl, 4-methoxy-phenyl, 4-ethoxy-phenyl, 4-tert-butyl-phenyl, thienyl, furyl, dibenzothienyl, dibenzofuranyl, carbazolyl, 4-fluoro-phenyl, 3-fluoro-phenyl, 4-carbazole-phenyl, 4-aldehyde-phenyl, 3-aldehyde-phenyl, 2-aldehyde-phenyl, 4-thiomethyl-phenyl, 4-cyano-phenyl, 4-trifluoromethyl-phenyl, and 4-nitro-phenyl.

[0019] Optionally, the chiral heptad metal cluster belongs to the hexagonal crystal system, space group R3.

[0020] Optionally, the chiral heptad metal cluster is selected from one of the structures shown in (1) to (8);

[0021]

[0022]

[0023] According to the second aspect of the present application, a method for preparing the chiral hepta-coin metal cluster compound described above is provided, and the preparation method comprises:

[0024] Reaction of a mixture containing 1,1,1-tri(diphenylphosphino)methane, a silver acetylene compound, a binaphthol phosphate, a compound represented by formula II, and a solvent to obtain the chiral hepta-coin metal cluster;

[0025] The binaphthol phosphate is selected from R-binaphthol phosphate or S-binaphthol phosphate;

[0026] The silver acetylene compound has a structure shown in formula III;

[0027] M(MeCN)4(X) Formula II;

[0028] RC≡C-Ag Formula III;

[0029] In formula II, M and X are consistent with M and X described above;

[0030] In formula III, R is the same as R described above.

[0031] Optionally, the molar ratio of the 1,1,1-tri(diphenylphosphino)methane, the silver acetylene compound, the binaphthol phosphate, and the compound represented by formula II is 2:4:3:1 to 2:10:3:1.

[0032] Optionally, the molar volume ratio of the 1,1,1-tri(diphenylphosphino)methane to the solvent is 0.1 mmol:(10-20) mL.

[0033] Optionally, the molar volume ratio of the 1,1,1-tri(diphenylphosphino)methane to the solvent is independently selected from any value of 0.1mmol:10mL, 0.1mmol:12mL, 0.1mmol:15mL, 0.1mmol:18mL, 0.1mmol:20mL or a range between any two of the above.

[0034] Optionally, the molar volume ratio of the 1,1,1-tri(diphenylphosphino)methane to the solvent is 0.1 mmol:(10-15) mL.

[0035] Optionally, the solvent is selected from at least one of dichloromethane, chloroform, chlorobenzene, 1,2-dichloroethane, 1,3-dichloropropane and acetonitrile.

[0036] Optionally, the reaction temperature is 20 to 60° C., and the reaction time is 4 to 24 hours.

[0037] According to a third aspect of the present application, a diode is provided, the diode comprising a light-emitting layer;

[0038] The light-emitting layer is selected from the chiral seven-coin metal cluster compound described above;

[0039] The diode includes one of an organic light emitting diode and a circularly polarized organic light emitting diode.

[0040] Optionally, the weight of the chiral heptad metal cluster accounts for 1 to 100% of the total weight of the diode light-emitting layer.

[0041] Optionally, the weight of the chiral heptad metal cluster is independently selected from any value among 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or a range between any two of the above to the total weight of the diode light-emitting layer.

[0042] Optionally, the weight of the chiral heptad metal cluster accounts for 5-60% of the total weight of the diode light-emitting layer.

[0043] Optionally, the weight of the chiral seven-coin metal cluster accounts for 40% of the total weight of the diode light-emitting layer.

[0044] According to a fourth aspect of the present application, a method for preparing the diode described above is provided, the method comprising the following steps:

[0045] S1: sequentially preparing a hole transport layer and a hole injection layer on a substrate by a solution spin coating method to obtain a substrate containing a hole injection layer;

[0046] S2: preparing a light-emitting layer on a substrate containing a hole injection layer by a solution spin coating method to obtain a substrate containing a light-emitting layer;

[0047] S3: on a substrate containing a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode material are sequentially prepared by vacuum thermal evaporation to obtain the diode;

[0048] The vacuum degree of the vacuum thermal evaporation method is 4×10 -4 ~4×10 -5 Pa.

[0049] Optionally, the structure of the organic light emitting diode and the circularly polarized organic light emitting diode preferably includes the following functional layers: a glass substrate, an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode layer.

[0050] Optionally, the hole injection layer, the hole transport layer and the light-emitting layer in the organic light-emitting diode and the circularly polarized organic light-emitting diode are prepared by solution spin coating.

[0051] Optionally, the anode is indium tin oxide (ITO).

[0052] Optionally, the hole injection layer is poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT:PSS), and the hole transport material is poly(bis(4-phenyl)(4-butylphenyl)amine) (Poly-TPD).

[0053] Optionally, the material having hole transport properties is selected from at least one of mCP (1,3-bis(9-carbazolyl)benzene), 2,6-DCZPPY (2,6-bis(3-(9-carbazolyl)phenyl)pyridine), TAPC (4,4′-cyclohexylbis(N,N-bis(4-methylphenyl)aniline)), and TCTA (tris(4-(9-carbazolyl)phenyl)amine).

[0054] Optionally, the material having electron transport properties is selected from at least one of OXD-7 (1,3-bis(5-(4-(tert-butyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene), BmPyPb (3,3",5,5"-tetra(3-pyridyl)-1,1':3',1"-terphenyl), TmPyPb (1,3,5-tri((3-pyridyl)-3-phenyl)benzene), TPBi (1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene), and BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0055] Optionally, the light-emitting layer contains a chiral heptaknuclear metal cluster compound as shown in formula I and a host material, wherein the host material is selected from at least one of TCTA, mCP, 2,6-DCZPPY, OXD-7, BCP, and TPBi, and more preferably 2,6-DCZPPY and OXD-7 (mass percentage is 1:1).

[0056] Optionally, the electron injection layer material is LiF.

[0057] Optionally, the cathode material is metal Al.

[0058] Optionally, the preferred diode structure is: ITO / PEDOT:PSS (50nm) / Poly-TPD (30nm) / 30wt% 2,6-DCZPPY:30wt% OXD-7:40wt% chiral heptaknuclear metal cluster shown in Formula I (50nm) / BmPyPb (50nm) / LiF (1nm) / Al (100nm).

[0059] According to the fifth aspect of the present application, there is provided an application of the above-mentioned diode in the fields of flat panel display, daily lighting, three-dimensional display, biosensing, and encryption and anti-counterfeiting.

[0060] Optionally, the organic light emitting diode and circularly polarized organic light emitting diode can be used in the fields of flat panel display and daily lighting, and can be further applied to the fields of three-dimensional display, biosensing, encryption and anti-counterfeiting by utilizing its circularly polarized light emission.

[0061] As an optional implementation, the present application is implemented through the following technical solutions:

[0062] The specific reaction equation is as follows:

[0063]

[0064] (1) Pour the ligand 1,1,1-tri(diphenylphosphino)methane and the silver acetylene compound (RC≡C-Ag) into a dichloromethane solvent and stir;

[0065] (2) Then, binaphthol phosphate and M(MeCN)4(X) were poured into the solution of step (1) and stirred for 4 hours to prepare a chiral heptanuclear metal cluster.

[0066] Optionally, the M(MeCN)4(X) refers to Ag(MeCN)4(X) or Cu(MeCN)4(X).

[0067] Optionally, the method for preparing the organic light-emitting diode and the circularly polarized organic light-emitting diode comprises: (1) preparing the hole injection layer and the hole transport layer in the organic light-emitting diode and the circularly polarized organic light-emitting diode by solution spin coating; (2) preparing the light-emitting layer comprising the chiral hepta-nuclear metal cluster compound doped with formula I by solution spin coating; (3) preparing the light-emitting layer by vacuum thermal evaporation (vacuum degree less than 4×10 -4 Pa) method to sequentially evaporate the electron transport layer material, electron injection layer material and cathode material of the device.

[0068] In the present application, the term "C1-C20 alkyl" should be understood to preferably mean a linear or branched saturated monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a C1-C20 alkyl group. "C1-C10 alkyl" should be understood to preferably mean a linear or branched saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, or the like or isomers thereof. In particular, the radical has 1, 2, 3, 4, 5 or 6 carbon atoms ("C1-C6 alkyl"), for example methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, more particularly, the radical has 1, 2 or 3 carbon atoms ("C1-C3 alkyl"), for example methyl, ethyl, n-propyl or isopropyl.

[0069] In the present application, the term "C2-C20 alkenyl" is understood to mean a linear or branched monovalent hydrocarbon radical containing one or more double bonds and having 2 to 20 carbon atoms, preferably "C2-C10 alkenyl". "C2-C10 alkenyl" is understood to preferably mean a linear or branched monovalent hydrocarbon radical containing one or more double bonds and having 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms ("C2-C3 alkenyl"), it being understood that in the case where the alkenyl contains more than one double bond, the double bonds may be separated from each other or conjugated. The alkenyl group is, for example, vinyl, allyl, (E)-2-methylvinyl, (Z)-2-methylvinyl, (E)-but-2-enyl, (Z)-but-2-enyl, (E)-but-1-enyl, (Z)-but-1-enyl, pent-4-enyl, (E)-pent-3-enyl, (Z)-pent-3-enyl, (E)-pent-2-enyl, (Z)-pent-2-enyl, (E)- Pent-1-enyl, (Z)-pent-1-enyl, hex-5-enyl, (E)-hex-4-enyl, (Z)-hex-4-enyl, (E)-hex-3-enyl, (Z)-hex-3-enyl, (E)-hex-2-enyl, (Z)-hex-2-enyl, (E)-hex-1-enyl, (Z)-hex-1-enyl, isopropenyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl , 2-methylprop-1-enyl, (E)-1-methylprop-1-enyl, (Z)-1-methylprop-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E)-2-methylbut-2-enyl, (Z)-2-methylbut-2-enyl, (E)-1-methylbut-2-enyl, (Z)-1-methyl but-2-enyl, (E)-3-methylbut-1-enyl, (Z)-3-methylbut-1-enyl, (E)-2-methylbut-1-enyl, (Z)-2-methylbut-1-enyl, (E)-1-methylbut-1-enyl, (Z)-1-methylbut-1-enyl, 1,1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, 1-propylvinyl, 1-isopropylvinyl.

[0070] In the present application, the term "C2-C20 alkynyl" is understood to mean a straight or branched monovalent hydrocarbon radical containing one or more triple bonds and having 2 to 20 carbon atoms, preferably a "C2-C10 alkynyl". The term "C2-C10 alkynyl" is understood to preferably mean a straight or branched monovalent hydrocarbon radical containing one or more triple bonds and having 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms ("C2-C3 alkynyl"). The alkynyl group is, for example, ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 1-methylprop-2-ynyl, 2-methylbut-3-ynyl, 1-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, 3-methylpent-4-ynyl, 2-methylpent-4 In some embodiments, the alkynyl group is ethynyl, prop-1-ynyl or prop-2-ynyl.

[0071] In the present application, the term "C3-C20 cycloalkyl" is understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3 to 20 carbon atoms, preferably "C3-C10 cycloalkyl". The term "C3-C10 cycloalkyl" is understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. The C3-C10 cycloalkyl may be a monocyclic hydrocarbon group, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, or a bicyclic hydrocarbon group such as a decalin ring.

[0072] In the present application, the term "C6-C20 aryl" is understood to mean a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6 to 20 carbon atoms, preferably "C6-C14 aryl". The term "C6-C14 aryl" is to be understood as preferably meaning a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms ("C6-C14 aryl"), in particular a ring having 6 carbon atoms ("C6 aryl"), for example phenyl; or biphenyl, or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C10 aryl"), for example tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C13 aryl"), for example fluorenyl, or a ring having 14 carbon atoms ("C14 aryl"), for example anthracenyl.

[0073] The term "C5-C20 heteroaryl" is understood as including monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5 to 20 ring atoms and containing 1 to 5 heteroatoms independently selected from N, O and S, for example "C5-C14 heteroaryl". The term "C5-C14 heteroaryl" is understood as including monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, in particular 5 or 6 or 9 or 10 carbon atoms, and containing 1 to 5, preferably 1 to 3 heteroatoms each independently selected from N, O and S and, in each case, may additionally be benzo-fused. In particular, heteroaryl is selected from thienyl, furanyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thiazolyl -4H-pyrazolyl and the like and their benzo derivatives, such as benzofuranyl, benzothiophenyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl, etc.; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, etc., and their benzo derivatives, such as quinolyl, quinazolinyl, isoquinolyl, etc.; or azinyl, indolizinyl, purinyl, etc. and their benzo derivatives; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, etc.

[0074] Unless otherwise indicated, heterocyclyl, heteroaryl or heteroarylene includes all possible isomeric forms thereof, such as positional isomers thereof. Thus, for some illustrative non-limiting examples, pyridyl or pyridylene includes pyridine-2-yl, pyridine-2-yl, pyridine-3-yl, pyridine-3-yl, pyridine-4-yl and pyridine-4-yl; thienyl or thienylene includes thien-2-yl, thien-2-yl, thien-3-yl and thien-3-yl.

[0075] The above definition of the term "C1-C20 alkyl" is also applicable to other terms containing "C1-C20 alkyl", such as the terms "C1-C2 alkoxy", "C1-C20 haloalkyl", etc.

[0076] The beneficial effects of this application include:

[0077] The chiral seven-nuclear metal cluster compound provided by the present application has the advantages of high luminous efficiency, low toxicity, easy synthesis, low price and adjustable luminescent color. The chiral seven-nuclear metal cluster compound is ionic, soluble in common organic solvents, and is particularly suitable for preparing electroluminescent devices by solution method, reducing the cost of device preparation. The cluster compound has strong luminescence in solution and film state. It can be used as a guest, doped in a host material, and used to prepare an organic light-emitting diode. The binaphthol phosphate ligand used for the chiral seven-nuclear coin metal cluster compound has chirality (R-binaphthol phosphate / S-binaphthol phosphate), which can induce the seven-nuclear coin metal cluster compound to produce chirality, and further the cluster compound can be made to produce circularly polarized luminescence, so that the chiral seven-nuclear coin metal cluster compound can be used as a chiral luminescent material to prepare a circularly polarized electroluminescent diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 Figure 1 is the crystal structure diagram of the cluster compounds (1) and (2) in Examples 1 and 2 of the present application. Figure a is the X-ray single crystal diffraction structure diagram of the cluster compound (1) in Example 1, and Figure b is the X-ray single crystal diffraction structure diagram of the cluster compound (2) in Example 2.

[0079] Figure 2 These are the emission spectra of the solutions and solids of cluster compounds (1) and (2) in Examples 1 and 2 of the present application under 365 nm excitation. Figure a is the emission spectrum of cluster compounds (1) and (2) in dichloromethane solution, and Figure b is the emission spectrum of cluster compounds (1) and (2) in solid powder.

[0080] Figure 3 Figure 1 is the circularly polarized emission spectra of the solutions and solids of the cluster compounds (1) and (2) in Examples 1 and 2 of the present application under 365 nm excitation, Figure a is the photoinduced circularly polarized luminescence spectrum of the cluster compounds (1) and (2) in dichloromethane solution, Figure b is the photoinduced circularly polarized luminescence asymmetry factor diagram of the cluster compounds (1) and (2) in dichloromethane solution, Figure c is the photoinduced circularly polarized luminescence spectrum of the cluster compounds (1) and (2) in solid powder, and Figure d is the photoinduced circularly polarized luminescence asymmetry factor diagram of the cluster compounds (1) and (2) in solid powder.

[0081] Figure 4The circularly polarized luminescence spectra generated by the circularly polarized electroluminescent devices of cluster compounds (1) and (2) in Examples 1 and 2 of the present application, Figure a is a diagram of the electro-induced circularly polarized luminescence spectra of cluster compounds (1) and (2) in a circularly polarized light-emitting diode, and Figure b is a diagram of the electro-induced circularly polarized luminescence asymmetry factor of cluster compounds (1) and (2) in a circularly polarized light-emitting diode. DETAILED DESCRIPTION

[0082] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0083] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0084] The crystal structures of the chiral heptad metal clusters (1)-(2) prepared in the following examples were determined by single crystal X-ray diffraction, and the unit cell parameters are shown in Table 1. The structures were further determined by high resolution electrospray mass spectrometry (HR-ESI-MS). The product purity of the obtained clusters (1)-(2) was determined by hydrogen nuclear magnetic resonance spectrum, phosphorus spectrum and elemental analysis (C, H and N).

[0085] In the present application, the chiral heptad metal cluster is selected from the clusters (1) to (8) shown below, wherein Ph in the structural formula of the clusters (1) to (8) represents a phenyl group:

[0086]

[0087]

[0088] According to an embodiment of the present invention, the chiral heptanuclear metal clusters (1) to (6) have unit cell parameters as shown in Table 1 below:

[0089] Table 1: Unit cell parameters of chiral heptad metal clusters (1) to (6)

[0090]

[0091]

[0092] Example 1 Preparation of Cluster Compound (1)

[0093] Weigh 0.1mmol, 28.5mg of 1,1,1-tri(diphenylphosphino)methane and 0.3mmol, 56.5mg of 4-(diphenylamino)phenyl)ethynylsilver, and add 15mL of dichloromethane. After stirring at room temperature for 15 minutes, add 0.15mmol, 52.3mg of R-binaphthol phosphate and 0.05mmol, 16.4mg of Cu(CH3CN)4ClO4, and then react for 4 hours at room temperature in the dark. After the reaction is completed, filter the reaction solution and remove the solvent with a rotary evaporator. Add ether and wash 3 times (3×10mL) to obtain a red powder with a yield of 85.2% (based on Cu(CH3CN)4ClO4). Nuclear magnetic resonance hydrogen spectrum and phosphorus spectrum tests show that a pure product is obtained (purity is 100%). Figure 1 As shown, Figure 1 Figure a is the X-ray single crystal diffraction structure of the cluster compound (1) in Example 1. It can be seen from Figure a that the cluster compound (1) is a 7-nuclear heterometallic cluster compound composed of 6 silver atoms and 1 copper atom. The metal core is surrounded by a ligand protection layer composed of 2 1,1,1-tris(diphenylphosphino)methanes, 3 4-(diphenylamino)phenylacetylenes and 3 R-binaphthol phosphates.

[0094] High resolution mass spectrometry: [M-ClO4] +

[0095] Calculated value: 3694.1722

[0096] Test value: 3694.1627

[0097] Elemental Analysis:

[0098] Calculated values: C: 61.41%; H: 3.72%; N: 1.11%;

[0099] Test values: C: 61.54%; H: 3.73%; N: 1.11%.

[0100] 1 H NMR(400MHz,Methylene Chloride-d2)δ8.55(d,J=8.8Hz,6H),7.91(dd,J=8.4,4.4Hz,19H),7.63(s,13H),7.43-7.35( m,13H),7.34-7.14(m,23H),7.13-6.94(m,46H),6.90(t,J=7.3Hz,7H),6.51(t,J=7.5Hz,12H).

[0101] 31P NMR (162MHz, Methylene Chloride-d2) δ13.15 (d, J = 567Hz, 6P), 11.45, 9.04 (3P).

[0102] Example 2 Preparation of Cluster Compound (2)

[0103] Weigh 0.1mmol, 28.5mg of 1,1,1-tri(diphenylphosphino)methane and 0.3mmol, 56.5mg of 4-(diphenylamino)phenyl)ethynylsilver, and add 15mL of dichloromethane. After stirring at room temperature for 15 minutes, add 0.15mmol, 52.3mg of S-binaphthol phosphate and 0.05mmol, 16.4mg of Cu(CH3CN)4ClO4, and then react at room temperature in the dark for 4 hours. After the reaction is completed, filter the reaction solution and remove the solvent with a rotary evaporator. Add ether and wash 3 times (3×10mL) to obtain a red powder with a yield of 86.2% (based on Cu(CH3CN)4ClO4). Nuclear magnetic resonance hydrogen spectrum and phosphorus spectrum tests show that a pure product is obtained (purity is 100%). Figure 1 As shown, Figure 1 Figure b is the X-ray single crystal diffraction structure of the cluster compound (2) in Example 2. It can be seen from Figure b that the cluster compound (2) is a 7-nuclear heterometallic cluster compound composed of 6 silver atoms and 1 copper atom. The metal core is surrounded by a ligand protection layer composed of 2 1,1,1-tris(diphenylphosphino)methanes, 3 4-(diphenylamino)phenylacetylenes and 3 S-binaphthol phosphates.

[0104] High resolution mass spectrometry: [M-ClO4] +

[0105] Calculated value: 3694.1722

[0106] Test value: 3694.1627

[0107] Elemental Analysis:

[0108] Calculated values: C: 61.41%; H: 3.72%; N: 1.11%;

[0109] Test values: C: 61.74%; H: 3.74%; N: 1.11%.

[0110] 1H NMR(400MHz,Methylene Chloride-d2)δ8.59-8.49(m,6H),7.94-7.83(m,18H),7.62(s,12H),7.45-7.34(m,13H),7 .35-7.14(m,22H),7.15-6.95(m,46H),6.90(td,J=7.1,1.3Hz,8H),6.51(t,J=7.2Hz,12H).

[0111] 31 P NMR (162MHz, Methylene Chloride-d2) δ13.15 (d, J = 567Hz, 6P), 11.45, 8.96 (3P).

[0112] Example 3 Photoluminescence performance test of cluster compounds (1) and (2)

[0113] The excitation spectra, emission spectra, luminescence lifetimes and luminescence quantum yields of the cluster compounds (1) and (2) prepared in Examples 1-2 in dichloromethane solution and solid powder states were measured using an Edinburgh FLS1000 fluorescence spectrometer. The luminescence quantum yields of the samples were measured using an integrating sphere with a diameter of 142 mm. The specific results are shown in Table 2.

[0114] Table 2. Photoluminescence performance data of chiral heptad metal clusters (1) and (2) in dichloromethane solution and solid powder state

[0115]

[0116] As shown in Table 2, the dichloromethane solution and solid of cluster compounds (1) and (2) both show red light emission, with the maximum emission peak near 620nm. The luminescence quantum yields of cluster compounds (1) and (2) in dichloromethane solution can reach 91.8% and 90.3%, respectively. As an excellent luminescent material, they can be used to prepare organic light-emitting diodes, and further applied to lighting, flat panel display and other fields. The emission spectra of cluster compounds (1) and (2) in dichloromethane solution and solid powder state under light excitation are shown in the attached figure. Figure 2 , Figure 2Cluster 1 corresponds to cluster (1), and cluster 2 corresponds to cluster (2); Figure a shows the emission spectra of clusters (1) and (2) in dichloromethane solution. The figure shows that both clusters exhibit bright red light emission in dichloromethane solution, and their emission centers are located at 666nm and 667nm, respectively. Figure b shows the emission spectra of clusters (1) and (2) in solid powder state. Compared with the emission spectra in dichloromethane solution, the emission of these two clusters in solid powder is red-shifted, and their emission centers are shifted to 680nm and 683nm, respectively.

[0117] Example 4 Circularly polarized luminescence performance test of cluster compounds (1) and (2)

[0118] The circularly polarized luminescence properties of the cluster compounds (1) and (2) prepared in Examples 1-2 in dichloromethane solution and solid state were tested using a CPL-300 circularly polarized luminescence spectrometer, including the circularly polarized luminescence spectrum and the luminescence asymmetry factor. The specific results are shown in Table 3.

[0119] Table 3. Circularly polarized luminescence performance data of chiral heptad metal clusters (1) and (2) in dichloromethane solution and solid powder state

[0120]

[0121] It can be seen from Table 3 that under light excitation, cluster compounds (1) and (2) have circularly polarized luminescence properties in both dichloromethane solution and solid powder states. Cluster compound (1) exhibits negative circularly polarized luminescence signals in both solution and solid states, and cluster compound (2) exhibits positive circularly polarized luminescence signals in both solution and solid powder states. The luminescence asymmetry factors of the two in the solid powder state can reach -5.4×10 -3 and 5.2×10 -3 As shown in Table 3, clusters 1 and 2 exhibit excellent circularly polarized luminescence performance and can be used as a circularly polarized luminescent material to prepare circularly polarized electroluminescent diodes, which can be used in the fields of three-dimensional display, biosensing, encryption and anti-counterfeiting. The circularly polarized luminescence spectra of clusters (1) and (2) are shown in the attached Figure 3 , Figure 3 In the above, cluster 1 corresponds to cluster (1), and cluster 2 corresponds to cluster (2); Figure 3As can be seen in the figure, Figure a is the photoinduced circularly polarized luminescence spectrum of clusters (1) and (2) in dichloromethane solution, Figure b is the photoinduced circularly polarized luminescence asymmetry factor diagram of clusters (1) and (2) in dichloromethane solution, Figure c is the photoinduced circularly polarized luminescence spectrum of clusters (1) and (2) in solid powder, and Figure d is the photoinduced circularly polarized luminescence asymmetry factor diagram of clusters (1) and (2) in solid powder; As can be seen from Figure a and Figure c, clusters (1) and (2) both show mirror-symmetric photoinduced circularly polarized emission spectra in dichloromethane solution and solid powder. As can be seen from Figure b and Figure d, the photoinduced circularly polarized luminescence asymmetry factors of clusters (1) and (2) in solid powder are larger, and their sizes are -5.4×10 -3 and 5.2×10 -3 .

[0122] Example 5 Cluster compound (1) is used as a light-emitting material to prepare an organic light-emitting diode by a solution method

[0123] The cluster compound (1) prepared in Example 1 was used as a luminescent material and was doped at a weight percentage of 40% into a mixed host material of OXD-7 (30%): 2,6-DCZPPY (30%) as a luminescent layer to prepare an organic light-emitting diode, and the device structure was: ITO / PEDOT:PSS (20nm) / Poly-TPD (30nm) / 30%OXD-7:%2,6-DCZPPY:40wt%Cluster compound 1 (50nm) / BmPyPb (50nm) / LiF (1nm) / Al (100nm).

[0124] The ITO glass was cleaned with glass cleaning agent, then ultrasonically cleaned with pure water, acetone and isopropanol for 15 minutes, and finally treated with ultraviolet ozone for 40 minutes. First, saturated poly (3,4-ethylenedioxythiophene) - poly (styrene sulfonic acid) (PEDOT:PSS) was filtered and spin-coated on the ITO glass at 3600 rpm. Then it was placed in a blast drying oven and dried at 130 ° C for 20 minutes to obtain a 40nm thick hole transport layer. Secondly, the ITO glass coated with the hole transport layer was transferred to a glove box, and the filtered poly (bis (4-phenyl) (4-butylphenyl) amine) (Poly-TPD) chlorobenzene solution (20mg / ml) was spin-coated on the PEDOT:PSS film, and a 10nm thick hole injection layer was formed after annealing at 140 ° C for 20 minutes. After cooling to 25°C, a dichloromethane solution (concentration of 5 mg / ml) containing 1,3-bis(5-(4-(tert-butyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene (OXD-7) (30%): 2,6-DCZPPY (30%): 40wt% cluster 1 (weight percentage) was spin-coated onto the Poly-TPD film at a speed of 2400 rpm to form a 50nm thick light-emitting layer. The light-emitting layer was dried at 40°C for 25 minutes. Finally, the ITO substrate was placed in the evaporation chamber. When the vacuum degree was lower than 4×10 -4 When the thickness of the organic light-emitting diode device is 100 nm, a 50 nm thick BmPyPb electron transport layer, a 1 nm thick LiF electron injection layer, and a 100 nm thick Al electrode are sequentially thermally evaporated as the device cathode. When evaporating the Al electrode, a mask is required. The luminous area of ​​the organic light-emitting diode device based on the cluster compound (1) is 16 mm 2 .

[0125] In a dry air environment at room temperature, various performances of the light-emitting diode device are tested. The electroluminescent performance parameters include the turn-on voltage (V on , brightness is 1cd / m 2 Voltage), maximum brightness (L max ), maximum current efficiency (CE max ), maximum power efficiency (PE max ), maximum external quantum efficiency (EQE max ) and electroluminescence wavelength (λ EL ). These data are listed in Table 4.

[0126] Table 4. Performance data of organic light-emitting diodes prepared by using cluster compound 1 as a luminescent material

[0127]

[0128] As can be seen from Table 4, the organic light-emitting diode prepared by the solution method using cluster compound 1 as the light-emitting material exhibits excellent performance, and its maximum external quantum efficiency (EQE) can reach 26.7%.

[0129] Example 6 Cluster compounds (1) and (2) were used as luminescent materials to prepare circularly polarized organic light-emitting diodes by solution method

[0130] Using the method in Example 5, cluster compounds (1) and (2) were first used as luminescent materials and organic light-emitting diodes were prepared by a solution method. Then, their circularly polarized electroluminescence spectra were tested using a CPL-300 circularly polarized luminescence spectrometer.

[0131] The circularly polarized organic light-emitting diodes prepared by the solution method using cluster compounds (1) and (2) as luminescent materials exhibit excellent electro-induced circularly polarized luminescence performance. The circularly polarized electroluminescence wavelengths are 675nm and 677nm, respectively; the circularly polarized electroluminescence asymmetry factors are -0.6×10 -4 and 0.6×10 -4 The electro-induced circularly polarized luminescence spectrum of the cluster is shown in the attached Figure 4 , Figure 4 In the above, cluster 1 corresponds to cluster (1), and cluster 2 corresponds to cluster (2); Figure 4 As can be seen from the figure, a is the electro-induced circularly polarized luminescence spectrum of cluster compounds (1) and (2) in a circularly polarized light-emitting diode, and b is the electro-induced circularly polarized luminescence asymmetry factor diagram of cluster compounds (1) and (2) in a circularly polarized light-emitting diode; it can be seen from figure a that cluster compounds (1) and (2) exhibit mirror-symmetrical electro-induced circularly polarized luminescence spectra, and their electro-induced circularly polarized luminescence asymmetry factors are -5.2×10 -3 and 5.3×10 -3 (See Figure b).

[0132] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A chiral heptad metal cluster, characterized in that: The chiral heptad metal cluster has a structure shown in Formula I: In formula I, the valence state of M is +1; M is selected from copper or silver; X is selected from ClO4 - PF6 - CF3SO3 - 、BF4 - 、SbF6 - CF3CF2CF2CF2SO3 - One of; R is independently selected from one of C1-C20 alkyl, C6-C20 aryl, C5-C20 heteroaryl, C1-C2 substituted alkyl, C6-C20 substituted aryl, and C5-C20 substituted heteroaryl; The substituents in the substituted alkyl, substituted aryl, and substituted heteroaryl are independently selected from one of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, amino, halogen, C1-C20 haloalkyl, C6-C20 aryl, and C5-C20 heteroaryl; The heteroatom in the heteroaryl group is N.

2. The chiral heptad metal cluster according to claim 1, characterized in that: The R is independently selected from one of C1-C8 alkyl, C6-C12 aryl, C5-C12 heteroaryl, C1-C8 substituted alkyl, C6-C12 substituted aryl, and C5-C12 substituted heteroaryl; The substituents in the substituted alkyl, substituted aryl, and substituted heteroaryl are independently selected from one of C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C1-C12 alkoxy, C1-C12 haloalkyl, C6-C12 aryl, and C5-C12 heteroaryl; Preferably, the chiral heptad metal cluster belongs to the hexagonal system, space group R3.

3. The chiral heptad metal cluster according to claim 1, characterized in that: The chiral heptad metal cluster is selected from one of the structures shown in (1) to (8); 4. The method for preparing the chiral hepta-coin metal cluster according to any one of claims 1 to 3, characterized in that: The preparation method comprises: reacting a mixture containing 1,1,1-tri(diphenylphosphino)methane, a silver acetylene compound, binaphthol phosphate, a compound represented by formula II, and a solvent to obtain the chiral hepta-coin metal cluster; The binaphthol phosphate is selected from R-binaphthol phosphate or S-binaphthol phosphate; The silver acetylene compound has a structure shown in formula III; M(MeCN)4(X) Formula II; RC≡C-Ag formula III; In formula II, M and X are consistent with M and X in claim 1; In formula III, R is the same as R in claim 1.

5. The preparation method according to claim 4, characterized in that: The molar ratio of the 1,1,1-tris(diphenylphosphino)methane, the silver acetylene compound, the binaphthol phosphate, and the compound represented by formula II is 2:4:3:1 to 2:10:3:1; Preferably, the molar volume ratio of the 1,1,1-tris(diphenylphosphino)methane to the solvent is 0.1 mmol:(10-20) mL; Preferably, the molar volume ratio of the 1,1,1-tri(diphenylphosphino)methane to the solvent is 0.1 mmol:(10-15) mL.

6. The preparation method according to claim 4, characterized in that: The solvent is selected from at least one of dichloromethane, chloroform, chlorobenzene, 1,2-dichloroethane, 1,3-dichloropropane, and acetonitrile; Preferably, the reaction temperature is 20-60° C., and the reaction time is 4-24 hours.

7. A diode, characterized in that: The diode comprises a light emitting layer; The light-emitting layer is selected from the chiral seven-coin metal cluster compound according to any one of claims 1 to 3; The diode includes one of an organic light emitting diode and a circularly polarized organic light emitting diode.

8. The diode according to claim 7, characterized in that The weight of the chiral seven-coin metal cluster accounts for 1 to 100% of the total weight of the diode light-emitting layer; Preferably, the weight of the chiral heptad metal cluster accounts for 5-60% of the total weight of the diode light-emitting layer.

9. The method for preparing a diode according to any one of claims 7 to 8, characterized in that: The preparation method comprises the following steps: S1: sequentially preparing a hole transport layer and a hole injection layer on a substrate by a solution spin coating method to obtain a substrate containing a hole injection layer; S2: preparing a light-emitting layer on a substrate containing a hole injection layer by a solution spin coating method to obtain a substrate containing a light-emitting layer; S3: on a substrate containing a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode material are sequentially prepared by vacuum thermal evaporation to obtain the diode; The vacuum degree of the vacuum thermal evaporation method is 4×10 -4 ~4×10 -5 Pa.

10. Application of the diode according to any one of claims 7 to 8 in the fields of flat panel display, daily lighting, three-dimensional display, biosensing, and encryption and anti-counterfeiting.

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