Stimuli-responsive protection of optically excited triplet ensembles against deactivation by molecular oxygen

Abstract

Herein we demonstrate temperature-dependent sacrificial singlet oxygen scavenging properties of N-butyl-2-pyridone, ensuring efficient stimuli-responsive protection of densely populated excited triplet state ensembles against deactivation by molecular oxygen. As an acting external stimulus the temperature was chosen: it will be shown that at low temperature the concentration of singlet oxygen will be substantially lowered; in contrast, at elevated temperatures singlet oxygen will not be captured, and thus the optically excited densely populated triplet ensembles will be effectively depopulated. The singlet oxygen scavenging ability of N-butyl-2-pyridone demonstrates long-term protection of a triplet–triplet annihilation upconversion process against photooxidation.