Nanofibers doped with a novel red-emitting Europium complex: Synthesis, characterization, photophysical property and sensing activity toward molecular oxygen

Abstract

In this paper, we synthesize a novel diamine ligand of DIQ-Et and its corresponding Eu(III) complex of Eu(TTA)3DIQ-Et, where DIQ-Et=N-ethyl-10H-dipyrido-[f,h]-indolo-[3,2-b]-quinoxaline, and TTA=2-thenoyltrifluoroacetonate. The UV–vis absorption, photoluminescence, low temperature phosphorescence, energy transfer mechanism, and excited state lifetime of Eu(TTA)3DIQ-Et are investigated in detail. Data suggest that the emission of Eu(TTA)3DIQ-Et is quenchable by molecular oxygen due to the back-energy transfer process. By doping Eu(TTA)3DIQ-Et into a polymer matrix of poly(vinylpyrrolidone) (PVP), oxygen sensing performance of the resulted nanofibers is investigated. Finally, the 0.7wt% doped sample exhibits a linear response toward molecular oxygen, with a sensitivity of 2.4 and response/recovery time of 12s/16s.