National Natural Science Foundation of China [21072161]; National Basic Research Program of China (973 Program) [2012CB821600]; Program for Changjiang Scholars and the Innovative Research Team in University (PCSIRT) ; Reactions of the dihydride complex OsH2Cl2(PCy3)(2) (1) with HC CC(OH)Ph-2 at room temperature or under heating condition produce the hydride hydroxycarbyne complex OsHCl2[ CCH2C(OH)Ph-2](PCy3)(2) (2) and the hydride alkenylcarbyne complex OsHCl2( CCH = CPh2)(PCy3)(2) (3), respectively. Treatment of 2 or 3 with HCl center dot Et2O affords the trichlorocarbyne complex OsCl3( CCH = CPh2)(PCy3)(2) (4), which can be conveniently synthesized by the one pot reaction of 1 with HC CC(OH)Ph-2 in the presence of HCl center dot Et2O. Complex 4 can be alternatively prepared from the phosphine ligand substitution of the trichlorocarbyne complex OsCl3( CCH = CPh2)(PPh3)(2) (5) with PCy3, from which the mono-substituted intermediate OsCl3( CCH = CPh2)(PCy3)(PPh3) (6) can be isolated. Complex 4 undergoes ligand substitution reactions with water and pyridine leading to the formation of the aqua and pyridine-coordinate mono phosphine carbyne complexes OsCl3( CCH = CPh2)(PCy3)(S) (S=H2O, 7; S=Py, 8). In addition, complex 4 reacts with NaOEt at room temperature to produce the alkenylcarbene complex OsCl2(= CHCH = CPh2)(PCy3)(2) (9), which is unstable in solution and evolves into the thermally more stable hydride carbyne complex 3. In contrast, the reaction of 4 with EtOH can only take place at elevated temperature to give the hydride carbyne 3.