Study on a Rhenium(I) complex with oxadiazole-derived diamine ligand: Synthesis, characterization, photophysical property and luminescence response towards molecular oxygen

Here we report the synthesis, crystal structure, photophysical property and electronic nature of a Re(I) complex of Re(CO)3(POP)Br, where POP stands for 2-(5-phenyl-[1,3,4]oxadiazol-2-yl)-pyridine. Re(CO)3(POP)Br renders yellow phosphorescence peaking at 547 nm, showing a long excited state lifetime with biexponential decay pattern. Density functional calculation reveals that the emission comes from a triplet metal-to-ligand-charge-transfer excited state. We electrospun the composite nanofibers of Re(CO)3(POP)Br and polystyrene (PS), hoping to explore the possibility of using the composite nanofibers as an oxygen sensing material. The optimal sample with average diameter of ∼900 nm exhibits a maximum sensitivity of 7.07 towards molecular oxygen with short response time of 5 s due to the large surface-area-to-volume ratio of the nanofibers. No photobleaching is detected in these samples.