Electrochemical synthesis, single-crystal growth, physicochemical and dielectric studies of tetrabromobisphenol A

Abstract

A single crystal (30 mm × 13 mm × 8 mm) of organic molecular compound, viz. tetrabromobisphenol A (TBBP-A), was successfully crystallized by slow solvent evaporation technique. The raw material was synthesized from electrochemical process. The single-crystal diffraction study infers that it belongs to the monoclinic crystal system with the space group of C2/c. Structural perfection was elucidated from high-resolution X-ray diffraction analysis. The characteristic functional groups were identified by FT-IR and micro-Raman spectral studies. UV–Visible spectral analysis establishes its optical transparency in the entire visible region and absorption characteristics at 230 nm. The double refraction nature of the crystal was documented by the direct visualization method. Room-temperature PL analysis with the excitation wavelength of 275 nm has resulted in five emission peaks at 353, 376, 410, 418 and 488 nm. TG/DTA evidences the thermal stability of TBBP-A up to the melting point (160 °C) without any structural/phase change. Vickers micro-hardness test and its measured mechanical parameters have suggested that the titled material belongs to soft material category. From the dielectric measurement, the grown crystal exhibits high dielectric constant at low frequencies due to the contribution of ionic, electronic, space charge and orientational polarizations.