A novel Re(I) complex with oxdiazole moiety: Synthesis,characterization, photo- and electro-luminescence properties

In this paper, we report a novel phosphorescent Re(I) complex of Re(CO)₃(OP)Br, where OP = 2-(5-phenyl-[1,3,4]oxadiazol-2-yl)-pyridine, including its photophysical properties, geometric/electronic structures, electrochemical and thermal properties. Experimental data suggest that Re(CO)₃(OP)Br is a promising yellow emitter peaking at 545 nm with short excited state lifetime of ～0.06 μs. The Re(I) center localizes in a distorted octahedral field in Re(CO)₃(OP)Br and the emissive state of Re(CO)₃(OP)Br has metal-to-ligand-charge-transfer character, leading to the room-temperature phosphorescence. Further analysis reveals that Re(CO)₃(OP)Br has HOMO and LUMO energy levels at ?5.90 V and ?3.57 V respectively, as well as its high thermal decomposition temperature of 380 °C. Using Re(CO)₃(OP)Br as a dopant, an electroluminescence peaking at 560 nm is realized, with a maximum luminance of 4300 cd/m² and a maximum current efficiency of 11.3 cd/A.