Abstract
With rapid change with technology, Organic Light-Emitting Diodes (OLED) rise in the last decade. It's the key point that developemet of blue, green, red light emitting material.Our laboratory has also invested in this field and published series of high efficiency phosphorescent material in recent years. In the first part of this essay, we designed a new kind of SiO^P as ancillary ligand to synthesize a series of [(SiO^P)Ir(C^N)2] complexes with high phosphorescent efficiency. In the second part, we chose Os(II) as the central atom of complexes which was third row transition metal as same as Ir(III) and designed a tetra-chelated ligand NPh(fppz)2. The rigid structure of the new kind of complexes [PhN(fppz)2Os(phosphine)2) maybe can improve the effeciency of OLED devices.