Crystal Structure of 4,5-Bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole

A nonlinear optical chromophore, 4,5-bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole, was investigated by X-ray crystallography. The study focused on coplanarity among several aromatic rings, including phenyls and imidazole. Two phenyl rings with NMe 2 groups are twisted by 46.39(3)° from each other. However, they are twisted by 23.05(5)° and 46.84(3)° from the imidazole, respectively. These unequal twists were elucidated by different conjugation pathways from the donors to the acceptor. The phenyl ring with the NO 2 group is twisted by only 6.76(6)° from the imidazole.