Air/liquid Interface Studied With Sum Frequency Generation Vibrational Spectroscopy(SFG-VS) And Related Raman Spectra Studies

As one of the second order nonlinear optical techniques, sum frequency generation vibrational spectroscopy (SFG-VS) has interfacial selectivity and submonolayer sensitivity. In the past two decades, significant progresses have been made in the study of vibrational spectra, structure and dynamics of the molecular interfaces with the application of SFG-VS. This dissertation focuses on the experimental correction to the bond additivity model, which uses the known Raman and IR spectra for quantitative SFG-VS spectra analysis, and the SFG-VS measurements of the air/liquid interfaces of three isomeric xylene compounds. In the end the basic theory of Raman vibrational spectra are introduced and the depolarization ratio of the Raman spectral lines of methanol and acetonitrile are measured.This dissertation consists four chapters: In the first chapter we mainly introduce some basic concepts in interface studies, the history of the investigations on the air/liquid interfaces,and the basic principles of SFG-VS. In the second chapter, an empirical approach is used to make corrections to the bond additivity model with the known Raman and IR spectra. With the corrected ratios between theβiq ' j'k' tensor elements of the symmetric stretching (SS) and asymmetric stretching (AS) modes, all features in the SFG-VS spectra of the air/methanol and air/ethanol interfaces can be quantitatively interpreted. In the third chapter, the SFG...