Enhanced emission under proton stimuli based on a phenanthroimidazole derivative by switching the excited state type from the CT to the LE state

Abstract

We report herein a vertical donor–acceptor-structured molecule based on a phenanthroimidazole derivative with rare enhanced emission under proton stimuli, which was caused by a change in the excited state type from the charge transfer state to the localized excited state. This provides a new strategy for developing off–on-type proton stimuli-responsive emitters requiring no stringent conditions for different states of being.