Interaction of benzene (Bz) with Pt and Pt2: A theoretical study on Bz–Pt2, Bz2–Pt, Bz2–Pt2, and Bz3–Pt2 clusters

Abstract

Extensive ab initio calculations have been carried out on benzene (Bz)–platinum complexes (Bz–Pt2, Bz2–Pt, Bz2–Pt2, and Bz3–Pt2) using a variety of computational techniques. Both physisorbed structures and energetically lower chemisorbed species were found. Complete active space multiconfiguration self-consistent field (CASMCSCF), multireference singles and doubles configuration-interaction (MRSDCI), density functional (DFT), and Møller–Plessett second order perturbation (MP2) calculations were employed to predict Bzm–Ptn structures. While the DFT and MP2 calculations also consistent with the MRSDCI techniques predict chemisorbed structures to be lower, the CASMCSCF method seems to favor physisorbed structures. The effect of spin-orbit coupling on the binding energies of complexes with the Pt atom and the Pt2 dimer were considered. The computed dissociation energies are consistent with the relative abundance of these clusters found in the time-of-flight mass spectra. The low-energy staircase structures of Bz2–Pt, Bz2–Pt2, and Bz3–Pt2 complexes found in this study could be electrically conducting.