Executive Summary : | The study of how the hydrogen bonded network in water is structurally and dynamically perturbed by ions and other chemical and biological solutes is a significant area of interest. The problem becomes more complex when solutes have high charge density and concentration, as the solute effects can extend beyond the first hydration shells and cannot be deduced by just summing individual hydration shell effects due to substantial overlap of hydration shells and ion pair formation. Experimentally, structural and dynamical perturbations of hydrogen bonded networks are studied using vibrational spectroscopic techniques such as linear infrared spectroscopy and nonlinear techniques like transient hole burning, three pulse photon echo (3PEPS), and two-dimensional infrared (2DIR) spectroscopy. The interpretation of these spectral observations depends on theoretical dissection of the entire spectrum into various underlying structural and dynamical components.
The current project aims to investigate both linear and nonlinear vibrational spectroscopy of aqueous solutions using machine learning approach combined with molecular simulations and electronic structure calculations. The machine learning approach will provide a more accurate description of the variation of vibrational transition frequencies with thermal fluctuations of molecular configurations of the solutions. The project will deal with aqueous solutions of metal halide solutions, osmolytes and denaturants, trimethylamine N-oxide, tertiary butyl alcohol, urea, and other molecular solutes of chemical interest. |