Raman vibrational bands are sensitive to fluctuations in the molecular environment. Variations in the bandwidth and peak position can then be utilized to monitor molecular forces and interactions present in condense phases. Nuclear Magnetic Resonance (NMR) provides a convenient probe for the study of molecular reorientation in liquids since nuclear spin relaxation times are dependent on the details of molecular motion. Presented here is the solvent study of the Raman bandwidths and frequency displacements of the mode of the compounds CH3MCI3 (M = C, Si, Ge, Sn) in a number of solvents of widely varying molecular structure. Also, a detailed isotope dilution study of the modes in CH2CI2/CD2CI2 mixtures is presented. In this set of experiments, I observed broadening of the v1 mode of CH2C12 upon dilution,which is the first experimental observation of such behavior. The temperature-dependent carbon-13 relaxation times and nuclear Overhauser enhancements in neat dichloromethane were measured. In this study we found that the molecular reorientation of this molecule was highly anisotropic, but could be well characterized assuming quasi-symmetric top behavior. In addition, in order to gain a more complete understanding of the reorientational dynamics in dichloromethane, we analyzed the 13-C NMR relaxation of CH2CI2 both in "inert" …

HPLC has been used and can quickly determine several ions simultaneously. The method of determination described for transition metals [Cr(III), Fe(III), Ni(II), Co(II), Cu(II), Zn(II), Cd(II), Mn(II)] and [Ca(II), Pb(II)] using HPLC with UV-VIS detection is better than the PAR complexation method commonly used. The effects of both eluent pH and detector wavelength were investigated. Results from using different pHs and wavelengths, optional analytical conditions for the separation of [Ni(II), Co(II), Cu(II)], [Cr(III), Fe(III), Ca(II), Ni(II), Cu(II)], and [Ca(II), Zn(II), Pb(II)] in one injection, respectively, are described. The influence of adding different concentrations of Na_2EDTA solvent to the sample is shown. Detection limits, linear range, and the comparisons between this study and a post-column PAR method are given.

We report the attempted syntheses of two photochemical dimethylsilene precursors, both of which are derived from polyphenyl silanorbornadiene skeletons. Possible synthetic schemes and our results are reported herein. Photolysis of 1,2-divinyl-1,1,2,2-tetramethyl-1,2-disilane at room temperature in a cyclohexane solution of 1,3-butadiene produces 1,1-dimethyl-2-(vinyldimethylsilylmethyl) silene which is trapped in high yields to afford the E- and Z-1,1-dimethyl-2-(vinyldimethylsilylmethyl)-3-vinyl-1-silacyclobutanes in 42 and 29% yields, respectively, along with minor amounts of 1,1-dimethyl-2-(vinyldimethylsilylmethyl)-1-silacyclohex-3-ene, 9%. Low Pressure Flow Pyrolysis at 450º C of either the E- or Z-isomer provides a relatively mild thermal source of the silene in the gas phase. Two products, 1,1,3,3-tetramethyldisilacyclohex-3-ene and 2,2,5,5-tetramethyl-2,5-disilabicyclo[2.2.1]hexane, are formed from an intramolecular rearrangement of the silene. Other reactions of the 3-vinylsilacyclobutanes include geometric isomerization, ring expansion to the silacyclohex-3-ene, and a homodienyl-1,5-hydrogen shift to 3,3,6,6-tetramethyl-3,6-disiladeca-1,4,8-triene. Synthetic schemes, successful and unsuccessful, for hydrido silene, acylpolysilene, and fluorine substituted silene precursors are discussed in the final chapter.

The method utilizes both cation and anion concentrator columns in parallel as a preconcentration system. The preconcentrator system is loaded using a reagent delivery module operated for a specific time at a preset flow rate. Total injection volumes of 2-5 ml are routinely used. Various chromatograms are discussed along with detailed information concerning detection limits for sodium and chloride, the system operating conditions, and the solutions to other pitfalls which have arisen during the course of this work.