||Oxidation of a series of Ru(Et2dtc)2L2 (L=labile group) complexes were studied. Treatment of cis-Ru(Et2dtc)2(dmso)2 with I2 led to isolation of trimeric [Ru3(Et2dtc)6(dmso)2](I3)2, presumably via self-assembly. Reactions of Ru(Et2dtc)(PPh3)2(CO)(OTf) with N2H4[black circle]xH2O and NH2OH gave the structurally characterized Ru(Et2dtc)(PPh3)2(CO)(H2NNH2)(OTf) and Ru(Et2dtc)(PPh3)2(CO)(NH2OH)(OTf), respectively. A series of Ru complexes with bis(dialkylphosphornyl)imide [N(PR2S)2] (R=Ph, i-Pr) ligands were synthesized. Treatment of Ru(PPh3)3CI2 with K[N(PR2S)2] gave structurally characterized Ru[N(PR2S)2]2(PPh3) (R=Ph, i-Pr). Ru[N(PPh2S)2]2(PPh3) was found to catalyze hydrogenation of styrene to ethylbenzene. In addition, Ru[N(PPh2S)2]2(PPh3) reacted with both π acids (e.g. SO2, t-Bupy) and Lewis bases (e.g. NH3) to form a series of adducts. Novel Ru(II) diazene cis-Ru[N(PPh2)2]2(PPh3)(NH=NH) and sulfur monoxide cis-Ru[N(PPh2S)2]2(PPh3)(SO) complexes were isolated and structurally characterized. Stable nitrido and oxo-Os(VI) complexes trapls-Os(N)[N(PR2S)2]2Cl and trans-Os[N(PR2S)2]2O2(R=Ph, i-Pr) were also synthesized and structurally characterized. Acylimido-Re(V) species trans-Re(NCOCF3)[N(PPh2S)2]2(OCOCF3) and tracts-Re(NCOCHCl2)[N(PPh2S)2]2Cl can be isolated by acylation of Re(N)[N(PPh2S)2]2. Hydrolysis of acylimido-Re(V) [RCON=Re] gave Re=NH (for R=CF3, CCl3) and Re=O (for R=CH2Cl, CHCl2 and CH3) species, depending on the nature of R groups. A series of heterobimetallic nitrido-bridged complexes with a trioxo-Os(VIII) moiety were synthesized by metathesis reaction between [n-Bu4N][OsO3N] and [MLn][OTf] and were characterized by X-ray crystallography. Based on the structurally data, it was found that the nature of M-N-OS linkage depends on the electronic configuration of M. For d[to the power of 10]-d[to the power of 8]-configurated M (M=Au(I), Pt(II) and Ir(I)), the bonding is donor-acceptor type [M[back arrow]N[is equivalent to]Os]. For (NO)(por)Ru(NOsO3), the bonding can be described as [Os=N-Ru]. Reactions of [OsN(TolS2)2] with a series of organometallic electrophiles were studied. [Au(PPh3)]+ was found to attack the more basic sulfur while sterically bulky [Ir(PPh3)2(CO)]+ add to the less hindered nitride to yield (TolS2)OsN[STolSAu(PPh3)] and (PPh3)2(CO)IrNOs(TolS2)2, respectively.