On December 31, 1979, Larina, L. I.; Vakul’skaya, T. I.; Nefedova, O. B.; Shibanova, E. F.; Lopyrev, V. A.; Voronkov, M. G. published an article.Reference of 2-Nitro-1H-benzo[d]imidazole The title of the article was Study of electron effects of substituents in 2-substituted benzimidazole derivatives by a proton NMR method. And the article contained the following:
NMR chem. shifts (δ) were determined for the protons on C-4 and C-7 and on C-5 and C-6 of 2-substituted benzimidazoles and their anions and protonated forms. In the neutral mols. substituent effects were transmitted to positions 4 and 7 exclusively by conjugation but were transmitted to positions 5 and 6 by both field and resonance mechanisms in a 1:3 ratio. In the anions transmission to positions 5 and 6 involved only conjugation, whereas transmission to positions 4 and 7 involved inductive and resonance effects in a 1:8 ratio. The effects in the protonated forms could not be separated The experimental process involved the reaction of 2-Nitro-1H-benzo[d]imidazole(cas: 5709-67-1).Reference of 2-Nitro-1H-benzo[d]imidazole
The Article related to nmr benzimidazole lfer, Physical Organic Chemistry: Spectral and Related Studies and other aspects.Reference of 2-Nitro-1H-benzo[d]imidazole
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem