88422-27-9Relevant academic research and scientific papers
ESR AND POLAROGRAPHY OF NITROAZOLES. 4. POLAROGRAPHIC STUDY OF NITROBENZIMIDAZOLES
Lopyrev, V. A.,Larina, L. I.,Baumane, L. Kh.,Shibanova, E. F.,Gavar, R. A.,et al.
, p. 1021 - 1026 (1984)
The electrochemical reduction of 2-substituted 5(6)-benzimidazoles has been studied with the aid of classical polarography and cyclic voltammetry in acetonitrile.The influence of the substituents in position 2 on the magnitudes of the half-wave potentials of the first stage is exerted by induction and resonance mechanisms with approximately the same contributions, and that on the magnitudes of the half-wave potentials of the second stage predominantly by the resonance mechanism.The posibilities of taking the radical-stabilizing factor ?. into account in the correlations are discussed.In order to study the 2-substituted 5(6)-nitrobenzimidazole series, their pKa values in acetonitrile have been determined by potentiometric titration.
Investigation of Benzimidazoles. 5. Transmission of the Substituent Effects in 2-Substituted 5(6)-Nitrobenzimidazoles Studied by 1H, 13C and 15N NMR Spectroscopy
Lopyrev, V. A.,Larina, L. I.,Vakul'skaya, T. I.,Larin, M. F.,Shibanova, E. F.,et al.
, p. 301 - 304 (1985)
The influence of substituents on the 1H, 13C and 15N NMR chemical shifts of 2-substituted 5(6)-nitrobenzimidazoles and their analogues labelled with 15N in the nitro group was investigated.It was found that the substituent effects are transmitted to the carbon and hydrogen nuclei in position 4-7 mainly by the resonance mechanism, but to the nitro-nitrogen atom with approximately equal contributions from the resonance and inductive components.Comparision of the transmission of substituent effect in nitrobenzimidazoles with para and meta derivatives of nitrobenzene showed that the nitro group seems to be more tightly conjugated with the benzimidazole fragment than with the benzene ring.
