Molecules containing sulfur-nitrogen bonds, like
sulfonamides, have long been of interest due to their many uses and chemical
properties. Understanding the factors that cause sulfonamide reactivity is
important, yet their continues to be controversy regarding the relevance of S-N
π bonding in describing these species. In this paper, we use sulfur K-edge
x-ray absorption spectroscopy (XAS) in conjunction with density functional
theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding
in sulfonamides, sulfinamides and sulfenamides. We explore the nature of
electron distribution of the sulfur atom and its nearest neighbors and extend
the scope to explore the effects on rotational barriers along the
sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations
confirm that sulfonamides, and the other sulfinated amides in this series, have
essentially no S-N π bonding involving S<sub>3p</sub> contributions and that
electron repulsion and is the dominant force that affect rotational barriers.
Determination of the Kinetic Constants of a Chemical Reaction in Heterogeneous Phase Using Parameterized Metaheuristics