Energetics of the ruthenium-halide bond in olefin metathesis (pre)catalysts

Abstract

A DFT analysis of the strength of the Ru-halide bond in a series of typical olefin metathesis (pre)catalysts is presented. The calculated Ru-halide bond energies span the rather broad window of 25-43 kcal mol(-1). This indicates that in many systems dissociation of the Ru-halide bond is possible and is actually competitive with dissociation of the labile ligand generating the 14e active species. Consequently, formation of cationic Ru species in solution should be considered as a possible event

The authors are grateful to the European Commission (FP7 grant CP-FP 211468-2 EUMET and CIG09-GA-2011-293900 to AP), to the Spanish MICINN (Ramon y Cajal contract RYC-2009-05226 to AP) and to the Royal Society (University Research Fellowship to CSJC). LC thanks ENEA (http://www.enea.it) and the HPC team for support as for using the ENEA-GRID and the HPC facilities CRESCO (http://www.cresco.enea.it) Portici (Naples, Italy)