COMPLEXATION OF REDOX-ACTIVE SURFACTANTS BY CYCLODEXTRINS.

The effects of cyclodestrins on the aggregation behavior and electrochpemical properties of N-ethyl-N prime -hexadecyl-4,4 prime -bipyridinium bromide (C//1//6VBr//2) and N-ethyl-N prime -bipyridinium bromide (C//1//8Br//2) were assessed by using electrochemical, optical, and surface tension techniques. The association constants of these two amphiphillic viologens with alpha - and beta -cyclodextrin (ACD and BCD) were determined by a condutance method. Values in the range 10**3-10**4 M** minus **1 were obtaiend for all four complexes. In the presence of ACD, the first reduction couple of both viologens exhibits reversible, diffusion-controlled voltammetric behavior. ACD also inhibits completely the formation of dimers from the corresponding cation radicals.