Switched fluorescence and photosensitization based on reversible ion-pairing†
Abstract
The close ion-pair of Ir(bdpSO3)(cod)(IMes)] is an efficient photosensitizer, while the solvent-separated anion is highly fluorescent. Controlling ion association governs the path of the excitation energy which is channeled either to the S1 state (fluorescence) or via intersystem crossing into the T1 state (1O2 generation). Modulation of NHC donation affects the photosensitizing properties and only electron-rich NHC provide highly efficient photosensitizers.