The reorientational motion of substituted benzenes in the crystalline state. Dielectric relaxation of orthodinitrotetramethylbenzene and orthodinitrotetrachlorobenzene

Dielectric relaxation measurements have been performed on monocrystals of orthodinitrotetramethylbenzene and orthodinitrotetrachlorobenzene in the frequency and temperature ranges 1 kHz-1000 MHz and 280–450 K, respectively. In addition, scanning calorimetric as well as X-ray measurements have been carried out. From the results obtained a possible mechanism has been suggested as regards the dielectric relaxation process.