Micro-structural investigations in the glacial state of triphenyl phosphite

A detailed structural description of the glacial state in triphenyl phosphite, based on Raman microspectroscopy investigations and a complementary structural analysis by X-ray diffraction, of a nano-structured glacial state, is reported in this paper. The optical images obtained for the glacial state, isothermally prepared at 214 K and 220 K, display contrasting effects typical of an heterogeneous system. Very large clusters of hexagonal shape are distinguished, and Raman microspectroscopy gives the opportunity to describe the structural organization inside these clusters. The diffraction pattern of a glacial state formed in a low-temperature range [210 K, 216 K], was calculated from the consideration of an isotropic crystallite size of 50 إ. The good agreement between the calculated and experimental diffraction patterns confirms that the glacial state is composed of crystallites of the stable crystalline phase coexisting with the non-transformed supercooled liquid according to the micro-structural analysis of a glacial state prepared at higher temperature (222 K). Raman spectroscopy and X-ray diffraction investigations provide the description of two structural organizations corresponding to the liquid and the crystalline states. No other structural organization was detected in TPP using (direct and indirect) structural probes.