Transition metal compounds containing alkynylsilyl groups − complexes with a metal-silicon bond

Two transition metal complexes containing alkynylsilyl groups and a metal−silicon bond (CpFe(CO)2SiMe2Ctriple bond; length of mdashCPh (1), Co(CO)4SiMe2Ctriple bond; length of mdashCPh (2)) have been synthesized by nucleophilic substitution (salt elimination) using both strongly and weakly nucleophilic metallates. No disturbing interactions of the metallate with the Ctriple bond; length of mdashC bond were observed. The synthesis of a third complex ((Ph3P)2RhClHSiMe2Ctriple bond; length of mdashCPh (3)) by oxidative addition was hampered by transition metal catalyzed reactions of the Si−H with the Ctriple bond; length of mdashC triple bond. The reactivity of 1 toward complexation and hydrosilylation of the Ctriple bond; length of mdashC triple bond was studied, leading to the trinuclear dicobaltatetrahedrane compound 1 ∗ Co2(CO)6 (4) and the vinylsilyl complex CpFe(CO)2SiMe2CH=CPh(SiEt3) (5), respectively. The complexes were characterized by NMR (1–5), IR (1–5), and UV/VIS spectroscopy (1, 3, 4) as well as X-ray crystallography (1–4).