Optical cavity enhancement of visible light-driven photochemical reaction in the crystalline state

Photochemical reactions enable the synthesis of energetically unfavorable compounds but often require irradiation with ultraviolet light, which potentially induces side reactions. Here, cavity strong coupling enhances the efficiency of an all-solid state photocyclization in crystals of 2,4-dimethoxy-β-nitrostyrene under irradiation with visible light. The exposure to visible light facilitates photocyclization by the transition to a lower polaritonic state, which is energetically lower than the original transition state.