The solid state structure of CI Disperse Orange 44

The crystal structure of CI Disperse Orange 44 has been solved using direct methods and refined by least squares to R = 0.095. The structure consists of planar azobenzene molecules stacked in columns up the b-axis. The asymmetric unit consists of two molecules which differ in the conformation of the terminal -CH2CH2CN groups. The molecular structures and solid state packing arrangements ave compared with previously published data. Crystal packing calculations and high resolution powder diffraction studies have been employed to examine the likely structure of a mixed crystal with CI Disperse Orange 44 as the 'host' and CI Disperse Red 54 as an 'incorporated impurity'.