What Role Does the Excited State Play in Phototoxicity?
Phototoxicity occurs when a chemical compound becomes toxic upon exposure to light. The excited state is a critical factor in this process. During the transition from the excited state back to the ground state, the molecule may undergo reactions that produce harmful byproducts, such as radicals or reactive intermediates. These byproducts can interact with biological molecules, leading to cell damage or death. Examples include the skin reactions caused by certain photosensitizing agents, which are often found in drugs or cosmetics.
