T. Szymanskabuzar, TUNGSTEN(II) CHLOROCARBONYLS AS ALKENE METATHESIS, ARENE ALKYLATION AND ALKYNE POLYMERIZATION CATALYSTS, Journal of molecular catalysis. A, Chemical, 123(2-3), 1997, pp. 113-122
Tungsten(II) chlorocarbonyl compound obtained by photochemical oxidati
on of W(CO)(6) with CCl4 is an active alkene metathesis catalyst, free
of any organometallic component. This indicates that the initially fo
rmed alkylidene ligand must come from the alkene. In toluene solution
the same tungsten(II) compound also acts as a highly active catalyst f
or the transformation of alkenes to alkyltoluenes. Tungsten(II) compou
nds, which are formed in photochemical oxidation of W(CO)(6) with Grou
p 14 tetrahalides, are extremely reactive at 25 degrees C in phenylace
tylene polymerization. The results reported here clearly demonstrate t
hat the formation of tungsten(II) might be an important event in the c
reation by Lewis acids (Group 14 tetrachlorides) of the catalytic acti
vity of tungsten(0) compounds.