New practical tungsten(VI) based catalyst systems for ring opening metathesis polymerisation

Tungsten(VI) complexes of the type trans-[WCl2(diol)(OAr)2] were studied as catalyst precursors for ROMP of norbornene and dicyclopentadiene. These compounds form active catalysts when treated by simple Grignard reagents, such as methyl magnesium iodide or neophyl magnesium chloride. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atmosphere techniques.