文摘
In this paper, the polarizable dipole-dipole interaction model was further developed via adding lone-pair dipole moment treatment for nucleobase adenine, cytosine, and guanine. Not only polar covalent bonds, such as C=O, C―O, N―H, C―H and O―H were regarded as bond dipoles, but also nitrogens with lone-pair electrons of adenine, cytosine, and guanine were regarded as lone-pair dipoles. The parameters needed were first determined by treating model complexes. The model was subsequently applied to a series of nucleobase- and nucleoside-containing hydrogen-bonded complexes to rapidly predict the equilibrium hydrogen bond distances and the intermolecular inte-raction energies. It was observed that the model developed in this work reproduce the MP2/6-31+G(d,p) and B3LYP/6-31+G(d,p) equilibrium hydrogen bond distances with a root mean square error of less than 0.004 nm and the counterpoise-corrected MP2/aug-cc-pVTZ intermolecular interaction energies with a root mean square error of less than 2.93 kJ/mol, which was also highly efficient, demonstrating that the model developed in this work was rea-sonable and useful.
