Transition metal alkyne complex

Such compounds are intermediates in many catalytic reactions that convert alkynes to other organic products, e.g. hydrogenation and trimerization.

For example, a variety of cobalt-alkyne complexes arise by the reaction of alkynes with dicobalt octacarbonyl.

For example, in the phenylpropyne complex Pt(PPh3)2(MeC2Ph), the C-C distance is 1.277(25) vs 1.20 Å for a typical alkyne.

When bonded side-on to a single metal atom, an alkyne serves as a dihapto usually two-electron donor.

For early metal complexes, e.g., Cp2Ti(C2R2), strong π-backbonding into one of the π* antibonding orbitals of the alkyne is indicated.

Cuprous chloride also catalyzes the dimerization of acetylene to vinylacetylene, once used as a precursor to various polymers such a neoprene.

Mechanistic studies suggest that this reaction proceeds by insertion of acetylene into a copper(I) acetylide complex.