Photoresponsive sulfone-based molecules: photoinduced electron transfer and heat/air-stable radicals in the solid state

Abstract

Photoinduced electron transfer (PET) with the formation of stable radicals plays an important role in many areas. In this work, PET and color change of two sulfone-based donor–acceptor molecules were observed for the first time in the solid state. Generation of radicals was confirmed by experimental and theoretical data. The radicals could be stable in the air and at high temperature (e.g. 105 °C) in the solid state. Introducing an electron-donating substituent (such as –NH₂) increases the molecular dipole moment and promotes the PET process. Sulfone-based molecules observed in this work and their analogs may be applied in several potential applications such as photoswitching, photochromism, energy conversion, and photocatalysis.