DFT study of conformational and vibrational characteristics of 2-(2-hydroxyphenyl)benzothiazole molecule

•Vibrational and conformational characteristics of 2-(2-hydroxyphenyl)benzothiazole have been investigated.•Out of four possible conformers, C-I, C-II, C-III, and C-IV, the C-I is the most stable conformer.•C-I and C-II are planar while C-III and C-IV are non- planar structures.•HOMO–LUMO and NBO analysis have also been performed.

The conformational and IR and Raman spectral studies of 2-(2-hydroxyphenyl)benzothiazole have been carried out by using the DFT method at the B3LYP/6-311++G** level. The detailed vibrational assignments have been done on the basis of calculated potential energy distributions. Comparative studies of molecular geometries, atomic charges and vibrational fundamentals of all the conformers have been made. There are four possible conformers for this molecule. The optimized geometrical parameters obtained by B3LYP/6-311++G** method showed good agreement with the experimental X-ray data. The atomic polar tensor (APT) charges, Mulliken atomic charges, natural bond orbital (NBO) analysis and HOMO–LUMO energy gap of HBT and its conformers were also computed.

Graphical abstractThe atomic orbital compositions of the frontier MO of the lowest energy conformer (C-I) of HBT are reproduced here.Figure optionsDownload full-size imageDownload as PowerPoint slide