PNNL

Abstract

We report a conformational analysis of N,N,N',N'-tetramethylsuccinamide. An initial set of geometries was obtained through an exhaustive conformer search with molecular mechanics. The structures were further optimized using density functional theory (DFT) with the generalized-gradient approximation. Single point energies on the DFT geometries are reported at the second-order M?ller-Plesset (MP2) levels. The lowest energy conformations were further optimized at the MP2 level. Geometries and relative energies for twenty-two conformations are reported. The geometries are rationalized in terms of rotational potential energy surfaces in simple compounds, intramolecular C-H???O hydrogen bonding, and dipole-dipole repulsion.