Electron density characteristics and charge transfer effect of hydrogen bond O-H•••Pt(II): atoms in molecules study and natural bond orbital analysis

In this report, we extended the works of Rizzato etal. [Angew. Chem. Int. Ed. 49, 7440 (2010)] on the nature of O-HPt hydrogen bond in trans-[PtCl2(NH3)(N-glycine)]H2O(1H(2)O) complex, by computational study of O-HPt interaction in [NBu4][Pt(C6F5)(3)(8-hydroxyquinaldine)], with emphasis on charge transfer effect in this interaction of platinum(II) and hydrogen atom. According to the crystallographic geometry reported by Jose Maria Casas etal., [NBu4][Pt(C6F5)(3)(8-hydroxyquinaldine)] possesses one O-HPt hydrogen bridging interaction, similar to the case in trans-[PtCl2(NH3)(N-glycine)]H2O(1H(2)O) complex. On the basis of topological criteria of electron density, we characterised this O-HPt interaction. Charge transferred between platinum(II) and sigma(*)(O-H) orbital in this complex was calculated by using NBO method. The stabilised energy associated to charge transfer was estimated using a direct proportionality, that is 2-3eV per electron transferred. Charge transfer effects in O-HPt hydrogen bonds were studied for these two complexes. Our results indicate that the interaction of O-HPt is closed-shell in nature with significant charge transfer, and that charge transfer effect is not negligible in the interaction of O-HPt. The second conclusion is different from the result of Rizzato etal.