High-temperature crystal chemistry of normal paraffins with even numbers of carbon atoms

Thermal deformations and phase transformations of evennumbered paraffins C_nH_2n+2(n=20, 22, and 24) have been investigated in a thermal X-ray diffraction study. In homologs with n=20 and 24, phase transformations occur in two steps: triclinic-to-orthorhombic and orthorhombic-to-hexagonal transitions. An orthorhombic rotator phase of even n-paraffins is described for the first time. A crystal-chemical model of the phase transformations of the homologs is suggested. St. Petersburg State University. Translated fromZhurnal Strukturmoi Khimii, Vol. 36, No. 5, pp. 790–798, September–October, 1995. Translated by L. Smolina