Mapping the polymorphic transformation gateway vibration in crystalline 1,2,4,5-tetrabromobenzene.

ABSTRACT: The thermosalient behavior of 1,2,4,5-tetrabromobenzene (TBB) is related to a temperature-induced polymorphic structural change. The mechanism behind the phase transition has been investigated in this work using low-frequency (10-250 cm^-1) Raman spectroscopy and solid-state density functional theory simulations. Careful adjustments of the probing laser power permitted thermal control of the polymorph populations and enabled high-quality Raman vibrational spectra to be obtained for both the β (low temperature) and γ (high temperature) forms of TBB. Numerous well-defined vibrational features appear in the Raman spectra of both polymorphs which could be assigned to specific motions of the solid-state TBB molecules. It was discovered that the lowest-frequency vibration at 15.5 cm

SUBMITTER: Zaczek AJ 

PROVIDER: S-EPMC6354909 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature