Session: Heterocycles & Aromatics:

The sulfonamide functional group is commonly prepared from the condensation of an amine with a sulfonyl chloride. Unlike a traditional amide with a carbonyl group, the lone pair of electrons of the nitrogen atom of a sulfonamide does not readily participate in resonance with the sulfonyl group. This has important implications in how the sulfonamide group affects the conformational mobility of a molecule. In this research project, a series of nitrogen heterocycles from aziridine to azocane were reacted with 2,4,6-tri-isopropylbenzenesulfonyl chloride to form secondary sulfonamides. All of these materials were characterized by IR, 1H and 13 NMR spectroscopy. A select few that crystallized were analyzed by x-ray diffraction. Concurrent to the synthetic efforts, the electronic structures were also analyzed using quantum computational methods in Spartan18. In this presentation, the data from spectroscopic and computational methods will be compared to determine the disposition of the sulfonamide group relative to the nitrogen heterocycle. The purpose of this investigation is to understand how both the nitrogen ring size and aryl moiety of the sulfonamide affect the overall conformation of the molecule.

Erika Abram

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