The coordinating ability of dithiafulvenyldiphenylphosphine (P-DTF) has been investigated with cis-W(CO)(4)(Piperidine)(2). As shown by the metal carbonyl complexes obtained, this redox-active vinylphosphine can act as a monodentate (P) and as a bidentate (P,S) ligand. Oxidation of cis-M(CO)(4)(P-DTF)(2), M = Mo and W, leads to the carbon-carbon bond formation between the two coordinated dithiafulvenyidiphenylphosphines. This chemical coupling of the dithiafulvenyl cores in the coordination sphere of M(CO)(4) (M = Mo, W) fragment has been studied in the presence of variois oxidizing agents. The use of (BrC6H4)(3)NSbCl6 or AgBF4 induces the formation of a fivemembered metallecycle with a vinylogous TTF backbone while DDQ leads to a six-membered metallacycle. The syntheses, crystal structures, and electrochemical properties of the complexes obtained are described.