Solvent effects on binding energy, stability order and hydrogen bonding of guanine-cytosine base pair

In this study, the effect of various solvents on the stability order, binding energy and hydrogen bond (HB) strength of cytosine-guanine (C-G) complex are investigated by using the density functional theory. The results show that the stability of cytosine-guanine complex in polar solvent is higher than non-polar solutions while it is lower than solution in vacuum. The binding energy of cytosine-guanine complex in polar solvent is lower than non-polar solutions. Its HB strength in polar solvent with respect to water as natural solvent is close to each other. The natural bond orbital and frontier molecular orbital analysis have been carried out from the optimized structure. The Quantum Theory of "Atoms in Molecules" (QTAIM) of Bader is also applied here to get more details about the nature of intermolecular interactions. Finally, the chemical properties have been presented to investigate the chemical stability of cytosine-guanine complex. (C) 2015 Elsevier B.V. All rights reserved.