OPTICAL PROPERTIES, THERMOCHROMISM AND CRYSTAL STRUCTURE OF PICRIC ACID-HEXAMETHYLBENZENE COMPLEX

Abstract The crystal structure of the picric acid-hexamethylbenzene 1:2 complex has been determined by the X-ray diffraction method. The crystals of the complex have the orange form and the yellow form. This orange crystal exhibits the thermochromism at about 116°C. This phenomenon was studied by measuring the temperature dependence of the IR and visible absorption spectra of the crystals of the picric acid-hexamethylbenzene complex and the deuterated complex.