Crystal structure of 2-[(E)-2-(4-bromophenyl)diazen-1-yl]-4,5-bis(4-methoxyphenyl)-1H-imidazole: the first example of a structurally characterized triarylazoimidazole

Abstract

The title compound, C23H19BrN4O2, is a product of an azo coupling reaction between 3,4-bis(4-methoxyphenyl)imidazole and 4-bromophenyldiazonium tetrafluoroborate. Its crystal structure was determined using data collected at 120 K. The molecule adopts a trans configuration with respect to the N=N double bond. The imidazole and aryl rings attached to the azo linkage are coplanar within 12.73 (14)°, which indicates significant electron delocalization within the molecule. In the crystal, the molecules form centrosymmetric dimers via pairs of N—H...O hydrogen bonds.