An ab initio model study of the cytosine - Methylbenzene interaction

The unconventional hydrogen bond involving the amino group as proton donor and benzene ring as proton acceptor was studied on the B3LYP/6-31G level. Medium effects were simulated by the Polarisable Continuum Model of Tomasi et al. Obtained results (hydrogen bond energy -1.28 kcal/mol, nitrogen - benzene distance 3.85 Angstrom) were discussed and compared with the data from the literature. To our knowledge this is the first attempt of treating the amino/benzene hydrogen bond with the inclusion of the medium.