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

The title compound, C(23)H(19)BrN(4)O(2), 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.