Raman studies of concentration, solvent, temperature, and pressure effects on molecular vibrations and isomerization equilibria
Abstract
This thesis describes experimental Raman studies of liquid mixtures of both analytical and fundamental interest. This includes the use of Raman spectroscopy to quantitate the concentration of liquid mixtures. Both peak area ratio and more sophisticated correlation algorithms are used to analyze the data. Raman peak intensities and shifts are used to study Fermi resonance in methanol and methanold-d4 solutions. Pressure and phase dependent Raman frequency shifts are used to obtain molecular forces and changes in bond length for different molecules, and to shed light on hydrogen bonding in molecular liquids. Raman scattering is also used to monitor the effects of pressure and temperature on the gauche-trans isomerization equilibrium of 1-chloropropane and 1,2-dichloroethane in diethyl ether. In this case both intensity ratio and frequency shift differences are used to probe the effects of dispersion and dipolar interactions on this model chemical reaction (folding reaction). The goal of these studies is to determine the repulsive and attractive contributions to the isomerization process and to see how these correlate with solvent parameters such as polarizability and dipole moment, molecular volume, etc. Comparison of frequency shift and isomerization equilibrium studies is used to probe the relationship between the solvation energy of the two isomers in the ground and excited vibrational states.
Degree
Ph.D.
Advisors
Ben-Amotz, Purdue University.
Subject Area
Chemistry|Analytical chemistry
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