A P1, Z=4 P1, Z = 2 phase transition in the 6, 6′- ( (propylazandiyl) bis (methylene) ) bis (4-methyl-2- (2-phenylpropan-2-yl) phenol) crystal is studied using a multi-temperature single crystal XRD experiment performed at 17 temperatures in the 90-220 K range. The mechanism of this transition is studied. It is shown that the phase transition proceeds over a wide temperature range and is accompanied by a correlated conformational transformation of propyl substituents. Intermolecular interactions stabilizing certain conformations of the propyl fragment are identified using the invariom model, and the role of these interactions in the crystal structure formation and evolution is discussed.
Lysenko et al. (Sun,) studied this question.