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