THERMOCHROMISM OF THE CRYSTALS OF 2,3-DI(P-CHLOROPHENYLTHIO)-1,4-NAPHTHOQUINONE

The crystals of 2,3-di(p-chlorophenylthio)-1,4-naphthoquinone have the dimorphs of red and dark red forms. The crystal structure of red form has been determined by the X-ray diffraction method. The red form cha nges to the dark red form upon heating. Such thermochromism was studie d by measuring the solid state CP/MAS and temperature variable IR abso ption spectra, and the DSC of the red form of 2,3-di(p-chlorophenylthi o)-1,4-naphthoquinone.