The intracomplex reaction of anthraquinone-2,6-disulfonate (AQDS) in triplet excited state ( 3 AQDS) with beta-cyclodextrin (CD) and the reaction of 3 AQDS:CD complex with external quencher, N -Acetyl- l -Tyrosine (TyrO − ), have been studied using laser flash photolysis, 1H NMR and 1H CIDNP. The two reactions were found to be competing with each other. The intracomplex hydrogen abstraction previously proposed for 3 AQDS:CD complex may represent a two-step process, where at first stage an electron is transferred from the –OH group of CD to 3 AQDS followed by a proton transfer and recombination of AQDS and CD radicals resulting in a stable AQDS-CD product. The rate constant of the intracomplex electron transfer from CD to 3 AQDS was found to be 6 ± 1 × 10 6 s −1 and the rate of subsequent proton transfer is 1 ± 0.1 × 10 6 s −1 . The rate constant of electron transfer between TyrO − and 3 AQDS:CD complex (0.4 ± 0.1 × 10 9 M −1 s −1 ) drops approx. by half compared to that in the reaction between TyrO − and free 3 AQDS (0.8 ± 0.1 × 10 9 M −1 s −1 ).

中文翻译：

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探索β-环糊精包裹的蒽醌-2,6-二磺酸盐的反应性

处于三重激发态 (3 AQDS) 的蒽醌-2,6-二磺酸盐 (AQDS) 与 β-环糊精 (CD) 的复合物内反应以及 3 AQDS:CD 复合物与外部淬灭剂 N-乙酰-l-酪氨酸的反应TyrO - )，已使用激光闪光光解、1H NMR 和 1H CIDNP 进行了研究。发现这两种反应相互竞争。先前为 3 AQDS:CD 复合物提出的复合物内氢提取可能代表一个两步过程，其中第一阶段电子从 CD 的 –OH 基团转移到 3 AQDS，然后是质子转移和 AQDS 和 CD 自由基的重组产生稳定的 AQDS-CD 产品。发现从 CD 到 3 AQDS 的复合内电子转移的速率常数为 6 ± 1 × 10 6 s -1 ，随后的质子转移速率为 1 ± 0.1 × 10 6 s -1 。TyrO - 和 3 AQDS:CD 复合物 (0.4 ± 0.1 × 10 9 M -1 s -1 ) 之间的电子转移速率常数下降了大约。与 TyrO - 和游离 3 AQDS (0.8 ± 0.1 × 10 9 M -1 s -1 ) 之间的反应相比，减少了一半。