Luminescent gold(iii) compounds with thermally stimulated delayed phosphorescence (tsdp) property for organic light-emitting devices and their preparation

Abstract

Described herein are a novel concept of thermally stimulated delayed phosphorescence (TSDP) to harvest light emission from the higher energy triplet excited state via the up-conversion from the lowest-energy triplet excited state by efficient spin-allowed reverse internal conversion as well as the development of TSDP emitters, as exemplified by a novel class of gold(III) compounds with TSDP properties and methods of making and using said compounds. The gold(III) compound includes a triazine-containing cyclometalating tridentate ligand and one auxiliary ligand, both coordinated to a gold(III) metal center. The gold(III) compounds disclosed herein can be used as light-emitting material for fabrication of OLEDs.

What is claimed: 
     
         1 . A luminescent gold(III) compound having a chemical structure shown in formula (I), 
       
         
           
           
               
               
           
         
         wherein: 
         (a) X, Y, Z 1  and Z 2  are each nitrogen or carbon; 
         (b) A and B are cyclic structure derivatives of unsubstituted or substituted phenyl groups or heterocyclic groups; 
         (c) R 1  is any carbon or heteroatom donor ligand, halide or pseudohalide, which could be either monoanionic or neutral, wherein R 1  is selected from, but not limited to, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, alkynyl, substituted alkynyl, alkoxy, amide, thiolate, phosphide, chloride, bromide, iodide, cyanate, thiocyanate or cyanide; 
         (d) R 2  is any carbon or heteroatom ligand, halide or pseudohalide, which could be either monoanionic or neutral, wherein R 2  is selected from, but not limited to, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, alkynyl, substituted alkynyl, alkoxy, amide, thiolate, phosphide, chloride, bromide, iodide, cyanate, thiocyanate or cyanide; and 
         (e) n is zero, a positive integer or a negative integer. 
       
     
     
         2 . The luminescent gold(III) compound of  claim 1  that exhibits thermally stimulated delayed phosphorescence properties. 
     
     
         3 . A light-emitting device with an ordered structure comprising an anode, a hole-transporting layer, a light-emitting layer, an electron-transporting layer and a cathode, wherein the light-emitting layer comprises the luminescent gold(III) compound as in  claim 1 . 
     
     
         4 . The light-emitting device of  claim 3 , wherein the light-emitting layer or emissive layer is prepared using vacuum deposition or solution processing technique. 
     
     
         5 . The light-emitting device of  claim 3 , wherein the light emitting layer comprises the material for light-emitting device as a dopant material. 
     
     
         6 . A light-emitting device with an ordered structure comprising an anode, a hole-transporting layer, a light-emitting layer, an electron-transporting layer and a cathode, wherein the light-emitting layer comprises a dopant material, and wherein the dopant material comprises the luminescent gold(III) compound as in  claim 1 . 
     
     
         7 . The luminescent gold(III) compound of  claim 1 , wherein rings A and B are independently benzene, phenyl derivatives, heterocycle or heterocyclic derivatives, but are not limited to, with one or more alkyl, alkenyl, alkynyl, aryl, cycloalkyl, OR, NR 2 , SR, C(O)R, C(O)OR, C(O)NR 2 , CN, CF 3 , NO 2 , SO 2 , SOR, SO 3 R, halo, aryl, substituted aryl, heteroaryl, substituted heteroaryl or heterocyclic group, wherein R is independently alkyl, alkenyl, alkynyl, alkyaryl, aryl, or cycloalkyl. 
     
     
         8 . The luminescent gold(III) compound of  claim 1 , wherein the gold(III) compound is deposited as a thin layer on a substrate. 
     
     
         9 . The luminescent gold(III) compound of  claim 8 , wherein the thin layer is deposited by vacuum deposition, spin-coating, or inkjet printing. 
     
     
         10 . The luminescent gold(III) compound of  claim 1 , wherein the gold(III) compound has photoluminescence properties within a range of about 380 to 1050 nm. 
     
     
         11 . The luminescent gold(III) compound of  claim 1 , wherein the gold(III) compound emits light in response to the passage of an electric current through the compound or to a strong electric field. 
     
     
         12 . An OLED comprising the gold(III) compound of  claim 1 . 
     
     
         13 . The OLED of  claim 12 , wherein the gold(III) compound is a dopant in the light-emitting layer or emissive layer of the OLED. 
     
     
         14 . The OLED of  claim 12 , wherein an emission energy of the OLED is independent of a concentration of the gold(III) compound and one or more donor groups on an auxiliary ligand, wherein the one or more donor group are selected from, but not limited to: N, S, O, P. 
     
     
         15 . The luminescent gold(III) compound of  claim 1 , wherein R 1  is a substituted or unsubstituted heterocyclic moiety selected from the group consisting of pyridine, thiophene, furan, pyrazole, imidazole, oxazole, isoxazole, thiazole, isothiazole, pyrrole, pyrazine, pyridazine, pyrimidine, benzimidazole, benzofuran, benzothiazole, indole, naphthalene, triazole, tetrazole, pyran, thiapyran, oxadiazole, triazine, tetrazine, carbazole, dibenzothiophene, dibenzofuran, fluorine, piperazine, piperidine, and pyrrolidine. 
     
     
         16 . The luminescent gold(III) compound of  claim 15 , wherein R 1  is a carbazole. 
     
     
         17 . The luminescent gold(III) compound of  claim 15 , wherein R 1  is a substituted heterocyclic moiety having an alkyl, alkoxy or aryl substituent. 
     
     
         18 . The luminescent gold(III) compound of  claim 1 , wherein R 1  is a substituted aryl. 
     
     
         19 . The luminescent gold(III) compound of  claim 18 , wherein a substituent of the substituted aryl of R 1  is a carbazole. 
     
     
         20 . The luminescent gold(III) compound of  claim 1 , wherein A and B are substituted alkyl groups. 
     
     
         21 . The luminescent gold(III) compound of  claim 20 , wherein A and B are 4-(tert-butyl)phenyl. 
     
     
         22 . The luminescent gold(III) compound of  claim 1  having the chemical formula: 
       
         
           
           
               
               
           
         
       
     
     
         23 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 4-(tert-butyl)phenyl. 
     
     
         24 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 4-(9H-carbazol-9-yl)phenyl. 
     
     
         25 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 9-methyl-9H-carbazol-3-yl. 
     
     
         26 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 9H-carbazol-9-yl. 
     
     
         27 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 3,6-di-tert-butyl-9H-carbazol-9-yl. 
     
     
         28 . The luminescent gold(III) compound of  claim 22 , wherein R 1  is 4-(tert-butyl)phenyl ethynyl.