Pentadiynylidyne and Pentacarbido Complexes

The reaction of the halocarbyne [W(≡CBr)(CO) 2 (Tp*)] (Tp*=hydrotris(3,5‐dimethylpyrazol‐1‐yl)borate) with trimethylsilyl‐butadiyne, mediated by [Pd(PPh 3 ) 4 ] and CuI, affords the first pentadiynylidyne complex [W(≡CC≡CC≡CSiMe 3 )(CO) 2 (Tp*)]. Desilylation provides a general route to heterobimetallic pentacarbido complexes, including [(Tp*)(CO) 2 W(μ‐C 5 )(PPh 3 ) 2 Ru(η‐C 5 H 5 )] and [(Ph 3 P) 2 (CO)HIr{(μ‐C 5 )W(CO) 2 (Tp*)} 2 ].