GENERATION OF TRANSITION-METAL CARBENE COMPLEXES AND THEIR RELATIVE ACTIVITY IN CHAIN PROCESSES OF CYCLO-OLEFIN RING-OPENING POLYMERIZATION AND OLEFIN METATHESIS

The interaction between CD3Li and WCl6 and MoCl5 was studied at various Li/W and Li/Mo ratios. It has been shown that the decomposition of the W or Mo organometallic intermediate leads to CD4, C2D6 and C2D4. The formation of CD4 is believed to be due to CD2:carbene creation in the system, while C2D4 is a product of the recombination of methylene fragments. At Li/W = 4 mol ratio, as well as in case of MoCl5, the decomposition appears to involve the formation of carbine complexes. The trimethylsilylmethylene complex which results from WCl6-induced decomposition of Me3SiCHN2 is shown to be a poor initiator of cyclopentene polymerization. Minor amounts of trimethylvinylsilane were found to inhibit cyclopentene polymerization and pentene-2 metathesis as a result of substitution of the active RCH:alkyl carbene for the more stable Me3SiCH:. © 1979.