1-(1H-Benzimidazol-1-ylmethyl)-3-[2-(diisopropylamino)ethyl]-1H-benzimidazolium bromide 0.25-hydrate

Abstract

The title N-heterocyclic carbene derivative, C23H30N5+·Br−·0.25H2O, was synthesized using microwave heating and was characterized by 1H and 13C NMR spectroscopy and a single-crystal X-ray diffraction study. The structure of the title compound are stabilized by a network of intra- and intermolecular C—H...Br hydrogen-bonding interactions. The crystal structure is further stabilized by π–π stacking interactions between benzene and imidazole fragment rings of parallel benzo[d]imidazole rings, with a separation of 3.486 (3) Å between the centroids of the benzene and imidazole rings. There is also an intermolecular C—H...π interaction in the crystal structure. The C—N bond lengths for the central benzimidazole ring are shorter than the average single C—N bond, thus showing varying degrees of double-bond character and indicating partial electron delocalization within the C—N—C—N—C fragment. The isopropyl group is disordered over two sites with occupancies of 0.792 (10) and 0.208 (10).