Electrochemical properties and computations of stable radicals of the heavy group 14 elements (Si, Ge, and Sn)

A series of stable radicals centered on persilyl-substituted heavy Group 14 elements, (tBu₂MeSi)₃E (E = Si, Ge, Sn), was studied by cyclic voltammetry in different solvents to determine their first oxidation and reduction potentials and to compare their ease of oxidation and reduction with known experimental and computed ionization energies (E_i) and electron affinities (E_ea), respectively. It has been observed that all of the first oxidation and reduction potentials for the three radicals studied are irreversible in o-dichlorobenzene (o-DCB), whereas the reduc-tion waves are quasi-reversible in THF. A good correlation has been found between measured oxidation potentials and ionization energy values, but no correlation between reduction potentials and electron affinity values was found, probably due to kinetic and surface effects.