Photoresponsive Behavior of Triphenylamine‐Based Organic Small Molecule Emitters Involving a Photo‐Induced Charge‐Transfer Complexation Mechanism under <scp>UV</scp> Light

Comprehensive Summary Stimuli‐responsive organic luminescent materials exhibit significant sensitivity to various external stimuli, among which their excellent photosensitivity is particularly prominent. This unique feature gives them great potential for applications. Herein, five organic small molecule emitters based on triphenylamine derivatives have been synthesized via Suzuki‐coupling reaction. These small molecules have excellent fluorescence properties with fluorescence quantum yields ( Φ ) all reaching over 90%. When irradiated with a 365 nm UV lamp, interesting photochromic phenomena occurred in their chloroform solutions. This phenomenon has been studied intensively by UV‐vis absorption and fluorescence spectroscopy, EPR measurements, and density functional theory calculations, and finally, the triphenylamine group was used as a photoinitiation precursor and electron donor, and the photo‐induced charge transfer complex (PCTC) initiated by the donor molecule was successfully constructed.