Conformational effects and cooperative interactions in poly[5(6)-vinylbenzimidazole]-catalyzed solvolyses of anionic, long-chain substrates

Abstract

A new synthetic procedure for the monomer, 5(6)-vinylbenzimidazole, has been developed. Also, a new method for the formation of the benzimidazole moiety is reported. The monomer, 5(6)-vinylbenzimidazole, was subjected to a free radical solution polymerization and a solid state thermal polymerization. Poly[5(6)-vinylbenzimidazole], prepared by the solution-free radical polymerization, was shown to he a linear addition polymer withpendant benzimidazole groups, whereas the thermally prepared polymer was shown to have a different structure. The solvolyses of negatively charged esters with varying aliphatic chain lengths catalyzed by poly[5(6)vinylbenzimidazole] and compared to monomeric benzimidazole in 40% lpropanol-water at 26°C revealed that the polymer was more efficient and that its activity was a function of the degree of ionization. Neutral-neutral and neutralanionic benzimidazole interactions are suggested. The polymer conformation was found to have a significant effect on the solvolysis reactions.