Synthesis, structure, and alkyne reactivity of a dimeric (carbene)copper(I) hydride

The monomeric, two-coordinate carbene complex (IPr)CuO-t-Bu (1) (IPr = 1,3-bis(2,6-diisopropylphenyl )imidazol-2-ylidene) reacts readily with silanes such as triethoxysilane, forming a dimeric copper(I) hydride complex (2) with a very short copper-copper distance. Hydrocupration of 3-hexyne by 2 affords a monomeric copper(I) vinyl complex.