Weak interactions defining the crystal packing in the sterically demanding compound 1-(3-methylphenyl)-2-(4-nitrophenyl)-4,5-diphenyl-1H-imidazole.

Abstract

The synthesis of 1-(3-methylphenyl)-2-(4-nitrophenyl)-4,5-diphenyl-1H-imidazole, C₂₈H₂₁N₃O₂, has been efficiently achieved in a one-pot procedure from simple materials. Its structure was analysed with the help of a full set of spectroscopic techniques, X-ray crystallographic studies and computational calculations, suggesting that the compound shows some potential for being used in nonlinear optical (NLO) devices. Despite being a sterically demanding tetrasubstituted imidazole, this compound can form a stable crystal structure based on the combination of a large set of weak interactions. With four aryl substituents, displaced and tilted edge-to-face and face-to-face aromatic-aromatic interactions are responsible of many of the short contacts identified, representing the major contribution as determined with the use of Hirshfeld surfaces. The nitro groups also play a key role, being responsible of the polarization of the molecule with the formation of antiparallel assemblies, leading to well-defined stacks. Antiparallel N...O pairs are also present at relatively short distances, together with short H...O contacts (16.9% contribution), indicating the presence of weak hydrogen bonds of the O atoms with weakly acidic H atoms in the polarized structure.