On the cis -> trans isomerization of the square-planar [Pt(Cl)(SnCl3)(PH3)(2)] compound: Ab initio gas phase reaction mechanism and solvent effects using continuum models

The cis --> trans isomerization of the dp square planar [Pt(CI)(SnCl3)(PH3) (2)] compound was investigated at the MP4(SDQ)/MP2 level of theory. The opt imized structures located on the gas-phase potential energy surface indicat e that this reaction proceeds through a quasi-tetrahedral transition state. The influence of electronic effects of the ligands on the reaction mechani sm was investigated with the Charge Decomposition Analysis (CDA) method, wh ich gave support to understand the strong trans effect of the SnCl3 ligand. The solvent effect on the gas phase energy reaction was evaluated using th e SCRF and IPCM continuum models. In both cases, an increase an the energy barrier for the process was observed and, the thermodynamical stability of the cis and trans isomers was changed upon salvation.