Dendrimers containing luminescent platinum(ii) compounds for organic light-emitting devices and their preparation

A method for preparing a luminescent compound with a cyclometalated tridentate ligand and at least one monoaryl group coordinated to a platinum(II) metal group, comprising the following reaction:

• wherein X and Y are independently selected from, but is not limited to, pyridine, imidazole, benzimidazole, naphthoimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, pyrazole, triazole, tetrazole, pyridazine, triazine, tetrazine, triazole, indole, oxazole, isoxazole, isothiazole, benzothiazole and benzoxazole, each being optionally substituted;
• Z is selected from, but is not limited to, benzene, naphthalene, anthracene, pyrene, fluorene, pyrene, pyridine, imidazole, benzimidazole, naphthoimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, pyrazole, triazole, tetrazole, pyridazine, triazine, tetrazine, triazole, indole, oxazole, isoxazole, isothiazole, benzothiazole, benzoxazole, thiophene, furan, benzofuran and dibenzofuran, each being optionally substituted;
• R1, R2 and R3 are the same or different and independently selected from hydrogen, alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, OR, NR2, SR, C(O)R, C(O)OR, C(O)NR2, CN, CF3, NO2, SO2, SOR, SO3R, halo, aryl, heteroaryl, heterocyclic group or a dendrimeric moiety of general formula (II), wherein R is independently alkyl, alkenyl, alkynyl, alkyaryl, aryl or cycloalkyl, and dendrimeric moieties, each being optionally substituted;
• R4 is an optionally substituted ligand attached to the platinum atom, in which, R4 is selected from, but is not limited to, halogen, alkyl, alkyl, cycloalkyl, alkenyl, arylalkenyl, aryl, alkynyl, arylalkynyl, heteroaryl, heterocyclic group, each being optionally substituted such as by a dendrimeric moiety of general formula (II).

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 platinum(II) compound having a chemical structure represented by the following general formula (I),

• wherein X and Y are independently selected from, but is not limited to, pyridine, imidazole, benzimidazole, naphthoimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, pyrazole, triazole, tetrazole, pyridazine, triazine, tetrazine, triazole, indole, oxazole, isoxazole, isothiazole, benzothiazole and benzoxazole, each being optionally substituted;
• Z is selected from, but is not limited to, benzene, naphthalene, anthracene, pyrene, fluorene, pyrene, pyridine, imidazole, benzimidazole, naphthoimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, pyrazole, triazole, tetrazole, pyridazine, triazine, tetrazine, triazole, indole, oxazole, isoxazole, isothiazole, benzothiazole, benzoxazole, thiophene, furan, benzofuran and dibenzofuran, each being optionally substituted;
• R1, R2 and R3 are the same or different and independently selected from hydrogen, alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, OR, NR2, SR, C(O)R, C(O)OR, C(O)NR2, CN, CF3, NO2, SO2, SOR, SO3R, halo, aryl, heteroaryl, heterocyclic group or a dendrimeric moiety of general formula (II), wherein R is independently alkyl, alkenyl, alkynyl, alkyaryl, aryl or cycloalkyl, and dendrimeric moieties with general formula (II), each being optionally substituted, with at least one of R1, R2, and R3 being a dendrimeric moiety;
• R4 is an optionally substituted ligand attached to the platinum atom;
• R4 is selected from, but is not limited to, halogen, alkyl, cycloalkyl, alkenyl, arylalkenyl, aryl, alkynyl and arylalkynyl, heteroaryl, heterocyclic, each being optionally substituted such as by a dendrimeric moiety of general formula (II);
• wherein:
• (i) Unit A is the central part of the dendron and the branching point of the dendrimer;
• (ii) Unit B is the surface groups or dendron of the dendrimer, or none.