INTRAMOLECULAR SPECIFIC C-H...N INTERACTIONS WITH PARTICIPATION OF THE PYRIDINE RING NITROGEN ATOM AND AMINO AND IMINO GROUPS IN 2-SUBSTITUTED 1-VINYLBENZIMIDAZOLES, ACCORDING TO H-1 AND C-13 NMR DATA

In 1-vinyl-2,2'-pyridylbenzimidazole, a double intramolecular specific C-H...N interaction is accomplished between the alpha-H of the vinyl group with the pyridine ring nitrogen and between the H-3' atom of the pyridine ring and the benzimidazole ring nitrogen. In 1-vinyl-2-aminobenzimidazole, there are no intramolecular interactions between the hydrogen atoms of the vinyl group and the nitrogen of the amino group. In 1,3-divinyl-2-iminobenzimidazole, the specific interaction of the imino group nitrogen with the beta-cis-hydrogen of the vinyl group is greatly weakened by a degenerate tautomeric equilibrium.