Theoretical Dynamics Study of Cytosine Tautomerism in the Gas Phase and Interaction of Na+ With Its Tautomers

The present study is an investigation of theoretical dynamics of cytosine tautomerism in the gas phase. MP2/6-311G(d,p) calculation have been carried out to investigate twenty two cytosine tautomers so that some of them have been reported for the first time. C3 and C20 are the most stable tautomers in gas phase. Interaction of cytosine tautomers with Na+ metal cation have been studied using MP2/6-31G(d,p). Three types of interaction of metal cations with cytosine tautomers have been investigated. The interaction between metal cation with both nitrogen and oxygen in which the lone pair of nitrogen is located close to the lone pair of oxygen. The second type of interaction is metal cation with a lone pair of nitrogen or oxygen. Third, the interaction between metal cation with two nitrogens.