Influence of N-Substitution on Electron Spin Resonance (ESR) Behavior of 2-(2-Nitrophenyl)-1H-benzimidazole Derivatives

Abstract

The synthesis of 2-(2-nitrophenyl)-1H-benzimidazole (1), 1-benzoyl-2-(2-nitrophenyl)-1H -benzimidazole (2), and 1-acetyl-2-(2-nitrophenyl)-1H-benzimidazole ( 3) is reported. Stable radical anions (1(center dot-), 2(center dot-), and 3(center dot-)) were generated by chemical reduction in DMSO and studied by ESR spectroscopy. The interpretation of the ESR spectra was done by means of computational simulation process. Hyperfine coupling constants were assigned by comparison with related compounds, and on the basis of calculation based on SCF INDO MO method in the unrestricted Hartree - Fock scheme.