Methanol dehydrogenation promoted by a heterobimetallic Ru(II)-Sn(II) complex as catalyst: A density functional study

Quantum mechanical calculations at the DFT level of theory were carried out to provide structural and energetic details of the methanol dehydrogenation mechanism promoted by homogeneous Ru(II)-Sn(II) catalyst. Structurally, it was obtained a reasonable agreement between the calculated and experimental geometric parameters. The β-hydrogen elimination step, which also includes the dissociation of the phosphines in a combined process, is found to be the rate determining step, with a considerable energy barrier of 28.42 kcal/mol. The global reaction is computed to be exothermic (ΔH = −29.98 kcal/mol) and spontaneous (ΔG = −46.94 kcal/mol). The energetics of some steps of the proposed catalytic cycle is found to be drastically affected by the inclusion of the solvent effects using PCM calculations. However, it does not change the overall trend obtained in gas phase.