Group VI Metal Complexes

Monomers with acetylene functionality are known to polymerize upon light irradiation in the presence of some metal carbonyls, like Cr(CO)6, Mo(CO)6, and W(CO)6 and some other group VI metal complexes. A variety of Lewis acids, like SiCU or GeCU are also effective catalysts for the polymerization of various acetylenes in nonchlorinated solvents. 

Although transmetallation is a key step in transition-metal catalysis, carbene transfer from one metal to another is rather rare. The transfer of a diaminocar-bene ligand between group VI metal complexes observed for the thermal dispro-... 

---