Aqueous electrochemistry of quaternary organoantimony ions

Article abstract of DOI:10.1021/ic50115a031

The series of quaternary organoantimony ions, (CH₃)_m(C₆H₅)_m-4Sb ⁺ (m = 1-4), has been studied in aqueous solution using dc polarography, cyclic voltammetry, and controlled potential electrolysis. Tetramethylantimony ion undergoes a single two-electron reduction to trimethylantimony and methane. The other three ions in the series are reduced in two one-electron steps. The first electron transfer involves the formation of an antimony(IV) species which rapidly reacts with the electrode metal to form an organomercury radical and a trivalent organoantimony compound. The organomercury radical disproportionates to form a diorganomercury compound. The second electron transfer gives trivalent organoantimony compounds and hydrocarbons. In two of the three possible cases both methyl and phenyl groups are lost by the antimony. The relative losses are different following the first and second electron transfer. Two factors govern the loss of the hydrocarbon group: the stability of the resulting hydrocarbon radical or carbanion and the stability of the resulting antimony compounds.