Room temperature phosphorescence lifetime and spectrum tuning of substituted thianthrenes

A group of thianthrene derivatives has been studied to investigate the effect of different substituents and substitution positions on their photophysical behavior. Strong room temperature phosphorescence (RTP) and dual fluorescence-phosphorescence at room temperature (RT-DFP) have been observed. Compounds with efficient (Φ ≈ 0.4) yellow and long-lived (τ = 88 ± 6 ms) green phosphorescence have been characterized. The involvement of nπ* and ππ* states was evaluated to explain their high triplet formation yield and phosphorescent properties. To give an insight into electron properties of studied molecules cyclic voltammetry and DFT calculations have been performed.