Journal of Electroanalytical Chemistry, Vol.374, No.1-2, 115-121, 1994
Effect of Alpha-Cyclodextrin and Beta-Cyclodextrin on the Electrochemistry of Methylheptylviologen and Dibenzylviologen
The electrochemistry of N-methyl-N’-heptyl-4,4’-bipyridinium (C1C7V2+) and N,N’-dibenzyl-4,4’-bipyridinium (BBV2+) salts with alpha-cyclodextrin and beta-cyclodextrin (CD) was studied. The cyclic voltammetric behavior of both viologens revealed a cyclodextrin-induced conproportionation reaction between the electrogenerated viologen neutral forms and viologen dications with beta-CD, but not with the alpha form. Both alpha-CD and beta-CD suppress dimerization of C1C7V.+, whereas only beta-CD is effective for disruption of the BBV.+ dimer. These results are interpreted in terms of the involvement of the bipyridine ring and benzyl group, depending on the oxidation state of viologen, in the inclusion complexation with beta-CD, but not significantly with alpha-CD.
Keywords:SODIUM DODECYL-SULFATE;METHYL VIOLOGEN;METHYLVIOLOGEN;ELECTRODES;INCLUSION;MICELLAR;SYSTEMS;CATION;ASSOCIATION;FILMS