Abstract: Reaction of trimethylsilyl reagents with Na [V (C0) 2 (dmpe) 2] leads to reductive coupling of the two CO ligands to form a coordinated bis (trimethy1siloxy) acetylene ligand. When Me3SiOTf was used, a novel six-coordinate, paramagnetic (pelt= 2.81 pB at 20 K)[V (Me3SiOC= COSiMe3)(dmpe) 2] OTf complex was obtained, while addition of Me3SiBr afforded diamagnetic [V (Me3SiOC= COSiMe3)(dmpe) 2Br], analogues of which are ...