Delineating conformation control in the room temperature phosphorescence and thermally activated delayed fluorescence behaviors: A first-principles investigation

It is a challenge for realizing room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) emissions from a single molecule and there is a strong demand for theoretical investigations to elucidate the relationship between molecular structures and photophysical properties. Herein, we explore the conformation-dependent photophysical behavior by first-principles calculations, inner physical parameters are studied and the impact of the structure changes on their RTP and TADF properties are delineated. Moreover, exciton transfer processes are clarified and excited states energy consumption processes are revealed. Our work rationalizes experimental observations and offers a theoretical perspective for regulating RTP and TADF features.