THEORETICAL AND EXPERIMENTAL STUDIES OF THE BARRIER TO AMINE ROTATIONIN CREATININE - INFLUENCE OF SOLVATION MODELS AND EXPLICIT SOLVATION

The barrier to rotation about the C-N(H-2) bond in creatinine in aqueo us environments has been studied experimentally, by means of NMR spect roscopy, and theoretically, employing a number of models based upon ex plicit solvation and continuum descriptions. The measured barrier to r otation (13 kcal mol(-1)) is obtained only if an explicit solvent is i ncluded in calculations on a supermolecule model; the use of a continu um model alone predicts a barrier (9 kcal mol(-1)), considerably small er than the experimental value.