| Various spectroscopic investigations are presented in this dissertation. Among these studies the ground (S0) and excited (S 1) electronic states of indan and 4,4'-dimethyl- trans-stilbene are investigated utilizing fluorescence, infrared, Raman and ultraviolet spectroscopies in detail. For indan, it is found that the barrier to planarity in the ground state is 488 cm-1 and 441 cm-1 in the excited state. Fluorescence excitation and dispersed fluorescence spectra for 4,4'-dimethyl- trans-stilbene are also presented. Analysis of this data shows that the phenyl torsions, the torsions about the C=C bond, and the other low frequency vibrations are all very similar to trans-stilbene and its methoxy derivative. It is also shown that the two methyl rotors are uncoupled with levels very similar to those of m-xylene. The vibrational spectra of p-cresol, with emphasis on the vapor-phase Raman spectra, are also analyzed. In this work, it is shown that in the vapor phase Raman spectra, the intensity ratio of the Fermi-doublet at 839/812 cm -1 is extraordinarily high as compared to previously reported results. From this study, correlations to the tyrosine signature Raman bands are made which show that this intensity ratio can be used to observe tyrosine in a non-hydrogen bonded local environment in proteins. The fourth investigation involves the van der Waals complexes of HCl-3-fluoropropene in cryosolutions. From the infrared spectra, it is shown that only sigma type complexes are observed, and the enthalpy of formation for the cis complex is calculated to be -9.6 kJ/mol. From the data presented, the enthalpy of formation for the gauche complex is estimated to be -10.4(5) kJ/mol. The last section of this study discusses the design and implementation of a dual stage time of flight mass spectrometer using photoionization as the ionization source. Several designs are discussed and analyzed in detail. |
