Phosphorescent Ir(iii) complexes with both cyclometalate chromophores and phosphine-silanolate ancillary: concurrent conversion of organosilane to silanolate

Abstract

Ir(III) metal complexes with general formula [(C^N)₂Ir(P^SiO)], where (C^N)H is 2-phenylisoquinoline (1), 2-phenylpyridine (2) or 2-(2,4-difluorophenyl)pyridine (3), and (P^SiO)H is an organosilanolate ancillary chelate with either diphenylsilyl (a) or dimethylsilyl (b) substituent, were synthesized, among which the structure of 3a was also confirmed using single-crystal X-ray diffraction analyses. These complexes exhibit bright phosphorescence in the region of 489–632 nm in solution at room temperature, showing the first successful example of using organosilanolate as an ancillary chelate. For application, organic light emitting diodes (OLEDs) using phosphors 3a and 3b doped in N,N′-dicarbazolyl-3,5-benzene (mCP) exhibited a maximum brightness of 50 800 cd m⁻² at 800 mA cm⁻² (12 V) with η_ext of 10.1% and a brightness of 45 900 cd m⁻² at 700 mA cm⁻² (14.5 V) with η_ext of 10.2%, respectively.