Catalytically active species in new metathesis systems [Wn+(Mon+)-ionic liquid-olefin]: A quantitative ESR study

A quantitative approach is successfully used in the ESR study of catalysts for olefin metathesis [Wn+(Mon+)-ionic liquid-olefin]. The key role of isolated complexes of W5+ and Mo5+ ions in catalysis is demonstrated. The kinetics of formation/accumulation of the isolated W5+ species at the initial step of W6+ reduction by an olefin agrees closely with the kinetics of metathesis.