Electronic structure of sulfur-nitrogen containing compounds : correlations with theory and chemical reactivity

Molecules containing sulfur-nitrogen bonds, such as sulfonamides, have long been of interest due to their many uses and chemical properties, including the potential release of nitric oxide and nitroxyl. Understanding the factors that cause sulfonamide reactivity is crucial, yet their inherent electronic complex- ity have made them difficult to examine. In this thesis, sulfur K-edge x-ray absorption spectroscopy (XAS) is used in conjunction with density functional theory (DFT) to determine the role of electronic transmission effects through the sulfur-nitrogen bond. A systematic deconstruction of the elements within the sulfonamide moiety is used as an approach to understand critical factors that dictate electronic structure. First, the effect of oxidation state changes and variations in R-group in sulfenamides, sulfinamides and sulfonamides on intramolecular bonding are explored. Next, N-hydroxylation of the sulfonamide amide, in both alkyl sulfonamides and a series of para-substituted aryl sulfonamides with varying Hammett para-sigma constants are studied using structure-function relationships, in conjunction with DFT, to understand the role of electron donation and withdrawal to the sulfonamide moiety. The outcome of these modifications on the sulfonamide framework lead to better insight towards directed drug design and its influence on nitroxyl and nitric oxide release.Science, Faculty ofChemistry, Department ofGraduat