Electrooxidation of Hypercoordinated Derivatives of Silicon and Reactivity of Their Electrogenerated Cation Radicals: 1-Substituted Silatranes

Electrochemical oxidation of 1-R-substituted silatranes 1 (R = Me, vinyl, (CH(2))(2)CN, CH(2)Ph, CH(2)(C(10)H(7)), Ph, C(6)H(4)Me, p-Cl-C(6)H(4), Cl)—classical representatives of pentacoordinated silicon compounds—and the formation of their short living cation radicals upon reversible or quasi-reversible one-electron withdrawal were studied by means of cyclic and square-wave voltammetry, faradaic impedance spectroscopy and real-time temperature-dependent EPR spectroelectrochemistry supported by DFT B3PW91/6-311++G(d,p) (C-PCM, acetonitrile) calculations. The main reaction responsible for the decay of 1(+•) is shown to be their deprotonation, and ways of increasing the stability of these species are proposed.