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DFT study of the full catalytic cycle for the propene hydroformylation catalyzed by a heterobimetallic HPt(SnCl3)(PH3)2 model catalyst
Authors:Júlio C S da Silva  Roberta P Dias  Wagner B de Almeida  Willian R Rocha
Institution:Departamento de Química, Laboratório de Química Computacional e Modelagem Molecular (LQC‐MM), ICEx, Universidade Federal de Minas Gerais, Campus Universitário, Pampulha, Belo Horizonte, Minas Gerais 31270‐901, Brazil
Abstract:DFT calculations were carried out to study the full catalytic cycle for the hydroformylation of propene, catalyzed by the heterobimetallic model catalyst trans‐Pt(H)(PH3)2(SnCl3). Before the study of the full catalytic cycle, the performance of six pure GGA, one GGA with inclusion of dispersion corrections, four hybrid‐GGA, and three meta‐GGA exchange correlation functional to describe a model reaction promoted by Pt‐Sn catalyst were assessed. It is shown that the BP86 and GPW91 functionals, using extended basis set, provides reliable energetic results when compared with the CCSD(T) calculations. All intermediates and transition states along the elementary steps of the entire catalytic cycle were located and the energies involved in the catalytic cycle calculated using BP86 functional. The solvent effects along the entire catalytic cycle were evaluated using the polarizable continuum model. In contrast with the rhodium catalysts, the regioselectivity of the hydroformylation is set at the carbonylation step. The hydrogenolysis is the rate determining step of the entire cycle, with the activation energy of ~21 kcal mol?1 in agreement with the experimental value of ~25 kcal mol?1. The trans effect of the SnClurn:x-wiley:01928651:media:JCC21483:tex2gif-stack-1 ligand seems to be pronounced only in the first step of the catalytic cycle, facilitating the insertion of the olefin into the Pt? H bond trans to it. The analysis of the stationary points obtained along each elementary step of the catalytic cycle is carried out separately and discussed. The BP86/cc‐pVTZ/SBKJC results shows that the pathway leading to the linear aldehyde is preferred, being in agreement with the experimental findings. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Keywords:DFT calculations  propene hydroformylation  Pt‐Sn heterobimetallic catalyst  regioselectivity
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