Reports: ND452801-ND4: The Fundamental Nature of Sulfur-Lone Pair Interactions

Dean J. Tantillo, University of California (Davis)

The Tantillo group has carried out quantum chemical calculations on a wide variety of molecules containing potential sulfur---lone pair interactions. Clear energetic preferences for having lone pairs next to sulfur (incorporated into aromatic heterocycles) have been observed. The origins of these structural preferences have been investigated using the full battery of available computational tools, and results indicate that orbital interactions aside from lone pair/S-X sigma* and lone pair/lone pair repulsion play key roles. Dispersion appears to contribute little. Electrostatics also contribute, but the relative contributions of various effects appear to be system dependent.