Resonance Raman (RR) is a ground state structural technique, but it can also be used to predict excited state structure at the harmonic minimum and the initial excited state dynamics in the Franck-Condon region by performing resonance Raman intensity analysis. In this thesis I have used RR spectroscopy to study a variety of systems, including the solvated electron, azobenzene and rhodamine 6G. Collectively, this work demonstrates the ability of resonance Raman spectroscopy to answer fundamental questions about the structure and dynamics of molecules in both the ground and excited states.

In my primary study, RR was used to investigate the structure and excited state dynamics of the solvated electron in methanol, ethanol, n-propanol, and n-butanol. The smaller downshifts of the OH stretch for e^-(EtOH), e^-(n-PrOH), and e ^-(n-BuOH) compared to the 340 cm^-1 downshift observed for e^-(MeOH) suggest that molecules in the first solvation shell change from bond- to dipole-oriented as the molecular structure of the alcoholic solvent is systematically lengthened. Raman intensity analysis supports a model in which librational motion is the dominant solvent response upon excitation of the electron and inhomogeneous mechanisms are largely responsible for the breadth of the absorption spectrum.

Cis- and trans-azobenzene are also studied using resonance Raman spectroscopy to elucidate their isomerization mechanisms. Resonance Raman spectra of the cis isomer exhibits intense low frequency modes at 275 and 594 cm^-1 assigned as CCNN and CNNC torsional modes, suggesting that the isomerization occurs via N=N bond rotation. The trans isomer exhibits the highest Raman intensity in high frequency bending modes, consistent with isomerization via inversion. The fluorescence quantum yields coupled with Strickler-Berg analysis predict excited state lifetimes of ∼200 fs and 3 ps for the cis and trans isomers, respectively. The non-planarity of cis-azobenzene appears to prime the molecule for rapid torsional isomerization.

The recently developed technique of broadband stimulated resonance Raman spectroscopy enables quantitative resonance Raman studies of fluorophores, such as rhodamine 6G (R6G) for the first time. R6G is frequently used in Surface-Enhanced Resonance Raman Spectroscopy (SERRS) experiments, yet enhancements due to molecular resonance and surface effects have not been properly separated. The stimulated resonance Raman cross-sections of rhodamine 6G have been quantified and a resonance Raman intensity-based Franck-Condon analysis performed. This analysis indicates that 10⁸ of the enhancement in SERRS experiments is due to molecular resonance.