Triplet excitation dynamics of β-carotene studied in three solvents by ns flash photolysis spectroscopy

• Published in: 中国化学快报：英文版 no. 1; pp. 83 - 88
• Main Author: Ying Jia Ying Shi Peng Wang Jian-Ping Zhang
• Format: Journal Article
• Language: English
• Published: 2017
• ISSN: 1001-8417; 1878-5964

Upon anthracene-sensitizing, triplet excitation dynamics of β-carotene(β-Car) were studied in nhexane, in methanol, and in acetonitrile, respectively, by ns flash photolysis spectroscopy. In n-hexane,only the bleaching of the ground state absorption(GSB) and the excitation triplet(~3Car*) absorption were observed, and there were no cationic species detected. In both methanol and acetonitrile, similar excitation dynamics were observed, i.e.,~3Car* having a similar lifetime to that in n-hexane, and the immediate generation of the cation dehydrodimer(~#[Car]2~+) upon excitation following transformation into the radical cation Car*~+, since Car*~+ has much longer lifetime in acetonitrile than in methanol. The results prove that both solvent and carotenoid structure determine the triplet excitation mechanism.