The Isomerization Equilibrium between Cis and Trans Chloride Ruthenium Olefin Metathesis Catalysts from Quantum Mechanics Calculations

• DOI: 10.1021/ja051796a
• Publication Date: 2005-08-31T04:39:31Z
• Authors: Diego Benitez; William A. Goddard
• Keywords: Methylene; Cis–trans isomerism

The cis−trans chloride isomerization of a ruthenium olefin metathesis catalyst is studied using quantum mechanics (B3LYP DFT), including the Poisson−Boltzmann (PBF) continuum approximation. predicted geometries agree with experiment. energies in methylene chloride, lead to ΔG = −0.70 kcal/mol and cis:trans ratio 76:24, quite close experimental value −0.78 or c:t 78:22. In contrast, we predict that benzene 4:96 agreement observation only trans isomer. Our calculated relative activation explain observed difference initiation rates suggest each isomer should be isolable high by simply changing solvent.