Improving oxygen sensing performance of Ir(III) complexes with fluorine atoms: Synthesis, characterization and sensing behavior of their electrospinning fibrous films

Abstract

In this paper, three Ir(III) complexes having large conjugation planes and F atoms in their ligands were designed and synthesized for optical oxygen sensing. These large conjugation planes and F atoms were supposed to broaden electronic distribution of excited electrons and prolong their decay lifetime. Sensing collision probability between excited electrons and O2 molecules was consequently increased, favoring oxygen sensing performance. To confirm this hypothesis, single crystal analysis and density functional theory calculation were carried out. Photophysical analysis on these Ir(III) complexes indicated that their emission had phosphorescent nature and was quenchable by O2 molecules. These Ir(III) complexes were doped into fibrous films using electrospinning method. Oxygen sensing behavior of these fibrous film samples was analyzed and compared. It was confirmed that large conjugation planes and F atoms in their ligands improved sensing performance. Finally, high sensitivity (15.56), short response (8s), good stability and linear-liked working curves were obtained.