Abstract
Density functional theory (DFT) was used to explore the different mechanistic possibilities for the hydrosilylation reaction between methyldimethoxysilane and methylvinyldimethoxysilane catalyzed by the Ru(II) complex dicarbonyldichlorobis(triphenylphosphine)ruthenium(II) (A1). Reaction enthalpy profiles of the Chalk−Harrod, modified Chalk−Harrod, and σ-bond metathesis mechanisms were computed for several different active forms of A1. A total of 10 different pathways with different catalytic cycles and different induction steps were compared. We predict that a σ-bond metathesis mechanism involving the formation of a hydride analogue of A1 is most favored, in contrast to the commonly accepted Chalk−Harrod mechanism of hydrosilylation. The B3LYP-calculated activation energy within the catalytic cycle (ΔHact = 21.8 kcal/mol) is small enough to make A1 a reasonable catalyst for this reaction under the normally applied experimental conditions
Original language | English |
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Pages (from-to) | 4504-4513 |
Number of pages | 10 |
Journal | Organometallics |
Volume | 25 |
DOIs | |
Publication status | Published - 2006 |
Keywords
- density functional theory
- Chalk−Harrod method
- hydrosilylations