Reactivity of electron donor-acceptor complexes. Catalytic reduction of methylene blue by aromatic hydrocarbons

Abstract

The hydrogen transfer from dihydro-aromatic hydrocarbons to Methylene Blue, catalyzed by aromatic hydrocarbons was studied, the Methylene Blue being regarded as a model compound of flavin co-enzymes. The reaction was always carried out in the absence of air at 0°C in 1,2-dichloroethane. The absorption peak of Methylene Blue at 659 nm was employed as a measure of the extent of the redox reaction. It was, consequently, found that Methylene Blue formed the EDA complexes (2 : 1) with various aromatic hydrocarbons, as was confirmed spectroscopically, and the reactivity of Methylene Blue was markedly affected by the formation of the EDA complexes in the redox reaction.