Theoretical study of the interaction d10-s2 between Pt(0) and Tl(I) on the [Pt(PH3)3Tl]+ complex

We studied the attraction between [Pt(PH3)3] and Tl(I) in the [Pt(PH3)3]-Tl+ complex using ab initio methodology. We found that the changes around the equilibrium distance Pt-Tl and in the interaction energies are sensitive to the electron correlation potential. This effect was evaluated using several levels of theory, including HF, MPn (n = 2-4), CCSD and CCSD(T). The obtained interaction energies differences at the equilibrium distance Re (Pt-Tl) range from 134 to 205 kJ/mol at the different levels used. At long-distances, the behaviour of the [Pt(PH3)3]-Tl+ interaction may be related mainly to charge-induced dipole and dispersion terms, both involving the individual properties of [Pt(PH3)3] and thallium ion. However, the charge-induced dipole term (R−4) is found as the principal contribution in the stability at the long and short distances. The dispersion interaction is smaller, but not negligible near equilibrium distance.