Electrochemistry ferrocene-gold complexes

Faulkner et al. performed surface-confined electrochemistry at high pressures to probe the structure of the transition state during the oxidation of a tethered ferrocene probe (analogous to System 4) [139]. In these studies, the ferrocene-containing SAMs on gold were subjected to pressures between 1 and 6000 atm. The pressure dependence of the anodic peak potential reveals a positive volume of activation for oxidation, which is consistent with a solvent reorganization in the transition state, which allows ion complexation. This study demonstrates the importance of structural and environmental effects on surface-confined electron-transfer processes. 

The electrochemistry of a square-planar gold(III) complex with 2-(diphenylphosphino) benzenethiolate (21) was reported by Dilworth and coworkers35. Cyclic voltammetry experiments on [Au(21)2]BPh4 indicate a reversible redox couple at —0.862 V (vs the Fc/Fc+ reference couple) in 0.2 M [Bu4N]BF4/MeCN solution. Peak-to-peak separation of the redox waves was 84.2 mV and convolution methods were used to establish that the redox couple was reversible and involved the same number of electrons as the ferrocene/ferrocenium couple under identical conditions. The reductive scan was assigned... 

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