An inner sphere electron transfer process via a cyanide bridge is proposed for the reactions of Cu(III,II) peptide complexes with Fe(CN) 6 3−,4− , Mo(CN) 8 3−,4− and W(CN) 8 3−,4− . Cu(III) peptide complexes were generated electrolytically from the Cu(II) precursors. The direction of spontaneous reactions is such that Fe(CN) 6 4− and W(CN) 8 4− reduce Cu(III) peptide complexes and Mo(CN) 8 3− oxidizes Cu(II) peptide complexes at pH ca. 10. However, since all reactions are equilibrium processes, by the very fast continuous decomposition of the reduced Cu(II) product in a slightly acidic reaction medium (pH 5), the Mo(CN) 8 4− reduction of Cu(III) peptide complexes could be driven to completion and studied kinetically. Kinetically determined equilibrium constants and electrochemically calculated equilibrium constants are mutually consistent. The experimentally observed inner sphere rate constants, k is , for these reactions are significantly larger than the corresponding outer sphere rate constant, k os , for the outer sphere electron transfer processes calculated with the Marcus theory, with or without work terms. It is concluded that if the kinetic advantage k is / k os is substantially larger than 1, it provides evidence for an inner sphere reaction pathway. The magnitude of the kinetic advantage of the present redox reactions varies from 1 to 63 and is dependent on the metal-to-metal distance in the cyanide-bridged intermediates.

中文翻译：

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铜(III,II)肽配合物与铁、钼和钨的氰基配合物的内球电子转移反应的动力学优势

Cu(III,II)肽复合物与Fe(CN) 6 3-,4- 、Mo(CN) 8 3-,4- 和W(CN)的反应提出了通过氰化物桥的内球电子转移过程。 ) 8 3−,4− 。Cu(III) 肽复合物是由 Cu(II) 前体电解产生的。自发反应的方向是 Fe(CN) 6 4- 和 W(CN) 8 4- 还原 Cu(III) 肽复合物，Mo(CN) 8 3- 在 pH 值约 2 时氧化 Cu(II) 肽复合物。10. 然而，由于所有反应都是平衡过程，通过还原的 Cu(II) 产物在微酸性反应介质 (pH 5) 中非常快速的连续分解，Cu(III) 的 Mo(CN) 8 4− 还原肽复合物可以被驱动完成并进行动力学研究。动力学确定的平衡常数和电化学计算的平衡常数是相互一致的。对于这些反应，实验观察到的内球速率常数 k 显着大于相应的外球速率常数 k os ，对于使用马库斯理论计算的外球电子转移过程，有或没有工作项。得出的结论是，如果动力学优势k is / k os 实质上大于1，则为内球反应途径提供了证据。本氧化还原反应的动力学优势的大小从 1 到 63 不等，取决于氰化物桥接中间体中金属与金属的距离。有或没有工作条款。得出的结论是，如果动力学优势k is / k os 实质上大于1，则为内球反应途径提供了证据。本氧化还原反应的动力学优势的大小从 1 到 63 不等，取决于氰化物桥接中间体中金属与金属的距离。有或没有工作条款。得出的结论是，如果动力学优势k is / k os 实质上大于1，则为内球反应途径提供了证据。本氧化还原反应的动力学优势的大小从 1 到 63 不等，取决于氰化物桥接中间体中金属与金属的距离。