Avobenzone CAS# 70356-09-1 阿伏苯宗

Avobenzone is a dibenzoylmethane compound commonly found in sunscreens and can photoisomerize after exposure to near-ultraviolet light. At equilibrium, Avobenzone exists as a chelated enol characterized by a strong intramolecular hydrogen bond. The photochemistry of Avobenzone includes keto-enol tautomerization, cis-trans isomerization, rotation about the single bond and α bond cleavages of carbonyl groups. Findings suggest that torsion around the double C2-C3 bond of photoexcited chelated enol leads to internal conversion to the ground state and formation of rotamer E. In addition, opening of the chelated hydrogen ring by torsion of the hydroxyl group creates non-chelated enol. The possible mechanisms of rotamer Z formation are discussed.