Synthesis and photochromism of a spirooxazine derivative featuring a carbazole moiety: Fast thermal bleaching and excellent fatigue resistance

A novel photochromic spirooxazine derivative bearing a carbazole moiety (SOC) was synthesized and studied in solution under flash photolysis conditions. It is found to exhibit excellent characteristics like high photochromic response, large steady-state optical density, fast thermal bleaching rate and good fatigue-resistance. The effect of different solvents on the photochromic properties of the compound was evaluated, revealing that the photochromic properties can be modulated by different solvents based on the corresponding polarity. The mechanism and kinetics of the thermal fading process of compound SOC were additionally investigated by theoretical simulations, where the isomerization pathway from the trans-trans-cis conformation was found to be several times faster than that from the cis-trans-cis conformation. This type of fast-bleaching and fatigue-resistent photochromic compounds is expected to pave an exciting avenue in future development of high-performance photochromic materials.