THE EFFECT OF HYDROGEN BONDING ON THE ELECTROREDUCTION BEHAVIOR OF AMINOBENZIMIDAZOLES 

Feyza Veyisoğlu,^a Mutlu Şahin,^b Nuran Özçiçek Pekmez,^a Muzaffer Can,^c and Attila Yıldız^a*
^a Hacettepe University, Department of Chemistry, 06532, Beytepe, Ankara, Turkey
^b Anadolu University, Department of Chemistry, 26470, Eskişehir, Turkey
^c Gaziosmanpaşa University, Department of Chemistry, Taşlıçiftlik, Tokat 60250, Turkey
* Corresponding author E-mail: yildiz@hacettepe.edu.tr

Abstract

The electroreductions of benzimidazole, 5-aminobenzimidazole, 2-aminobenzimidazole and 4-aminobenzimidazole were investigated on a Pt electrode in acetonitrile containing tetrafluoroborat (TBABF₄) with and without the presence of HBF₄. The presence of a proton donor gives rise to the catalytic reduction of protons through various types of protonated benzimidazoles at less negative potentials than those of the neutral hydrogen bonded benzimidazole clusters. The effect of inter-molecular hydrogen bonding on the electroreduction behavior was elucidated. The feasibility of the formation of the proposed hydrogen bonding was supported by the theoretical calculations.

Keywords: aminobenzimidazoles, hydrogen bond, electroreduction, theoretical investigation