Abstract: The binding of a series of square planar Pt(II) adducts on the Watson-Crick base pair AT and GC was investigated using advanced quantum chemical method. The result showed that the AT base pair was mainly influenced by electrostatic effect, the GC base pair was influenced by both electrostatic and polarization effect. The platinated purine and pyrimidine base pair was moderately strengthened, whereas interaction between the purine and pyrimidine base pair was slightly influenced compared with that of the isolated one. Further calculations on the Pd(II) and Ni(II) analogs showed a similar trend. The natural bonding orbital (NBO) analysis of the second-order perturbative energy ΔE2 well predicated strength of the H-bond in the base pair.

Key words: Pt (II) adduct, Pd (II) adduct, Ni (II) adduct, Base pair, Hydrogen bond, HF method, DFT