  Modulating heterogeneous microstructure in room temperature ionic liquids
(RTILs) by external stimuli is an important approach for understanding and
designing the external field induced chemical reactions in natural and
applicable systems. Here, we report for the first time the redistribution of
oxygen molecules in RTILs due to laser-induced microstructure changes probed by
triplet excited state dynamics of porphyrin and rotational dynamics of coumarin
153. A remarkably long-lived triplet excited state of porphyrin is observed in
air-saturated ionic liquid with the changes of microstructure after
irradiation, suggesting that more charge-shifted O2 induced by external laser
field move into the polar domains of ionic liquid [C8mim][PF6] from nonpolar
domains through electrostatic interactions. The results presented here suggest
that the heterogeneous systems of ionic liquids upon external stimuli can be
designed for those oxygen-related chemical reactions with extensive
inspirations for potential applications in lithium-air batteries, gaseous
sensing, photoelectrical catalysis and so on.
