Long Range Proton-Coupled Electron Transfer Reactions of Bis(imidazole) Iron Tetraphenylporphyrins Linked to Benzoates.
Long Range Proton-Coupled Electron Transfer Reactions of Bis(imidazole) Iron Tetraphenylporphyrins Linked to Benzoates.
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双(咪唑)铁四苯基卟啉与苯甲酸盐的长程质子耦合电子转移反应。
DOI：
10.1021/jz400029w
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Mayer,JamesM
中科院分区：
文献类型：
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作者：
Warren,JeffreyJ;Menzeleev,ArturR;Kretchmer,JoshuaS;Miller3rd,ThomasF;Gray,HarryB;Mayer,JamesM
使用实验和理论方法研究了羧基四苯基卟啉铁配合物中的协同质子电子转移（CPET）反应。合成血红素模型从羟胺 TEMPOH 或抗坏血酸衍生物中提取 H+ 和 e-，TEMPOH 反应的动力学表明 H+ 和 e- 的协同转移。亚苯基连接体结构域使电子供体/受体分离变化约 4 Å。速率数据和广泛的分子模拟表明，电子耦合衰减常数 (β) 取决于与连接域相关的构象灵活性和溶剂化。我们对 β 的最佳估计是 0.23 ± 0.07 Å–1，该值接近为涉及相关连接体的电子转移反应建立的范围 (0.2–0.5 Å–1) 的下限。这是首次对 CPET 反应的 β 进行分析。
Concerted proton–electron transfer (CPET) reactions in iron carboxytetraphenylporphyrin complexes have been investigated using both experimental and theoretical methods. Synthetic heme models abstract H+and e–from the hydroxylamine TEMPOH or an ascorbate derivative, and the kinetics of the TEMPOH reaction indicate concerted transfer of H+and e–. Phenylene linker domains vary the electron donor/acceptor separation by approximately 4 Å. The rate data and extensive molecular simulations show that the electronic coupling decay constant (β) depends on conformational flexibility and solvation associated with the linker domain. Our best estimate of β is 0.23 ± 0.07 Å–1, a value that is near the low end of the range (0.2–0.5 Å–1) established for electron-transfer reactions involving related linkers. This is the first analysis of β for a CPET reaction.