Models do exist to take solvent effects into account, but these models are only in their infancy and still require extensive testing and development.
Rotation is slow because of the partial double bond character indicated by the resonance structures.
The two methyl groups are in different chemical environments, and give rise to separate NMR signals. However, two surprising findings have emerged. First, in striking contrast to amides, the barrier did not depend on solvent hydrogen bond donor ability. As a representative approach using of explicit solvent molecules, Monte Carlo simulations were carried out with Jorgensen's BOSS package by Shoshannah Pearlman. The simulations strongly underestimated the influence of cyclohexane, consistent with earlier Monte Carlo studies of amides in non-polar solvents.