A phosphorescent copper(I) complex: Synthesis, characterization, photophysical property, and sensing performance towards molecular oxygen

In this paper, we report the synthesis, crystal structure, photophysical properties, and electronic nature of a phosphorescent Cu(I) complex of [Cu(PYB)(POP)]BF4, where PYB and POP stand for 2-pyridin-2-yl-1H-benzoimidazole and bis(2-(diphenylphosphanyl)phenyl) ether, respectively. [Cu(PYB)(POP)]BF4 renders yellow phosphorescence peaking at 561 nm, with a long excited state lifetime of 13.4 μs. Density functional calculation reveals that the emission comes from a triplet metal-to-ligand-charge-transfer excited state. We electrospun composite nanofibers of [Cu(PYB)(POP)]BF4 and polystyrene, hoping to explore the possibility of using the composite nanofibers as an oxygen sensing material. The finally obtained samples with average diameter of ∼900 nm exhibit a maximum sensitivity of 4.20 towards molecular oxygen with short response/recovery time (8 s/16 s) due to the large surface-area-to-volume ratio of nanofibrous membranes. No photobleaching is detected in these samples.