THE SOLID-STATE STRUCTURE OF CI-DISPERSE-ORANGE-44

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