(E)-4-(4-Bromophenyldiazenyl)-2,6-Dimethylphenyl Acrylate and (E)-2,6-Dimethyl-4-(4-Methylphenyl-Diazenyl)Phenyl Acrylate

Abstract

The crystal structures of the title compounds, C17H15BrN2O2, (I), and C18H18N2O2, (II), determined at room temperature, have a trans configuration with respect to the diazene linkage, as found for other azo (diazene) derivatives. The aromatic mean planes are nearly coplanar, with a dihedral angle between these planes of 8.31 (2)° for (I) and 3.74 (2)° for (II). In both complexes, the mean plane of the ester group is nearly perpendicular to the aromatic ring planes. In both compounds, the crystal packing involves only π-π and π-ring inter-actions, which combine to stabilize the extended structure. © 2007 International Union of Crystallography.