P1-Mof. RH como catalisador para a hidroformilação de olefinas: um estudo computacional

Abstract

In this work, quantum chemical calculations were carried out using density functional theory to evaluate the catalytical potential of rhodium-monophosphines, which correspond to the reactive center of the MOF material P1.MOF.Rh, in the hydroformylation reaction of terminal olefins. All intermediates and transition states and the coordination and insertion of the olefins, 1-propene, 1-butene, 1-pentene, 1-hexene, and styrene were located, and adequately characterized energies involved were calculated using the BP86-D2 functional with dispersion corrections. The energetic results obtained at the BP86-D2/def2-TZVP/LANL2TZ/PCM level showed that the regioselectivity of the reaction is already defined in the first step, with a kinetic preference by the linear reaction pathway for all olefins' hydroformylation. These results also showed that the coordination of the olefins to the P1.MOF.Rh catalyst and the formation of the Rh-alquil intermediate are spontaneous processes, and that once the p-complexes (coord), products of the first step, are formed, the olefins insertion into the Rh-H bond of the catalyst occurs with activation barriers < 7.0 kcal/mol. BP86-D2 calculations predict a selectivity above 75% in favor of the linear product at 80º, even for styrene, where usually the branched product is the preferred one. The overall analysis of the results showed that the Rh catalyst of P1.MOF.Rh is pro linear selective independent of the substrate's chemical nature and places it as a potential catalyst for the olefins hydroformylation reaction. Analysis of Hirshfeld charges and energy decomposition showed that the reaction's selectivity also depends on the chemical nature of the olefins.