The barrier to rotation about the C-N(H-2) bond in creatinine in aqueous environments has been studied experimentally, by means of NMR spectroscopy, and theoretically, employing a number of models based upon explicit solvation and continuum descriptions. The measured barrier to rotation (13 kcal mol(-1)) is obtained only if an explicit solvent is included in calculations on a supermolecule model; the use of a continuum model alone predicts a barrier (9 kcal mol(-1)), considerably smaller than the experimental value.
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