Vibrational Spectroscopic Investigation on Bisthiourea Magnesium Sulphate (BTMS) Using Experimental and Computational [HF and DFT] Analysis

Durga R, Anand S, Sundarara

Abstract

Nonlinear optical bisthiourea mixed magnesium sulphate BTMS crystals were synthesized and grown by slow evaporation method using water as solvent. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. These observations suggest that the metals coordinate with thiourea through sulphur. The observed peaks IR and Raman were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by HF and DFT methods with basis sets and the corresponding results were tabulated. UV-Vis-NIR spectra were recorded to study the optical transparency of the grown crystals. The observed Raman and infrared bands were also assigned and discussed. The optical transmission spectral study was carried out to test the transmitting ability of the crystal in the visible range. The second harmonic generation test of BTMS revealed the nonlinear nature of the crystal. The TGA/DTA curve was also recorded for the experimental crystal. The lattice parameters of the grown crystal have been determined by X-ray diffraction studies.