A. Mishra, C. Murli, K. Pandey
Dec 23, 2019
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0
Influential Citations
6
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Journal
The journal of physical chemistry. B
Abstract
Benzoic acid derivatives are important molecular systems in the pharmaceutical industry. Salicylic acid is distinct among the derivatives of benzoic acid due to the presence of an intra-molecular hydrogen bond. With a view to study the evolution of intra- and inter molecular hydrogen bonding at shorter length scales, in-situ high pressure Raman spectroscopic measurement, angle dispersive x-ray diffraction measurements and density functional theory (DFT) based first principle calculations have been carried out on crystalline salicylic acid. Subtle structural modifications are noted across ~ 1 GPa leading to structural phase transition to a new crystalline phase above 7 GPa which is reversible. Substantial softening of the OH stretching Raman mode associated with intra-molecular hydrogen bond is observed prior to the transition pressure. Possible molecular configurations associated with tautomerization are discussed with the aid of DFT calculations.