Electrocatalytic Reduction of α,ω-Diiodoalkanes I(CH2) m I (m = 1−8) by C60 n - (n = 1−3) Anions in Solution and at the C60 Film-Modified Electrodes

Electroreduction of a homologous series of α,ω-diiodoalkanes I(CH2) m I (m = 1−8) is shown to be catalyzed by C60 n - anions (n = 2, 3) both in solution and at a C60 film-coated electrode. Solution electrocatalysis occurred for the anions of n = 2 and 3 in 0.1 M (TBA)PF6 in benzonitrile at a platinum working electrode. Electrocatalysis at the film-coated electrode occurred for anions of n = 1 and 2 in 0.1 M (TBA)PF6 in acetonitrile. For solution electrocatalysis, the second-order catalytic rate constants were determined by voltammetry at a rotating disk electrode under pseudo-first-order conditions with respect to the α,ω-diiodoalkanes. The determined k values increase in the order C5 < C8 < C4 < C3 < C6 ≪ C2 for the number of carbon atoms of the alkyl chain of the α,ω-diiodoalkanes. The GC−MS and HPLC product analyses of the constant potential bulk electrolyses revealed that alkanes, alkenes, and monoiodoalkyl derivatives are formed primarily, except for the reaction of C60 3- with either 1,3-diiodopropane or 1,5-diiodopentane where formation of the C60 adducts is favored.