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

• 作 者: Ying Jia Ying Shi Peng Wang Jian-Ping Zhang
• 机 构: Department of Chemistry, Renmin University of China,
• 出 处: Chinese Chemical Letters
• 发表日期: 2017年01期
• 关键词: excitation acetonitrile methanol hexane lifetime carotene cationic singlet longe

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.

After 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 In both methanol and acetonitrile, similar excitation dynamics were observed, ie, ~ 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. prove that both solvent and carotenoid structure determine the triplet excitation mechanism.