Dioxo- and nitrido-osmium complexes with imidodiphosphinochalcogenido ligands [N(QPR(2))(2)](-) (Q = S or Se; R = Ph or Pr-i)

Reactions of trans-K-2[(OsO2)-O-VI(OH)(4)] with 2 equivalents of HN(QPR(2)) (2) yielded the dioxoosmium(VI) complexes trans-[OsO2{N(QPR(2))(2)}(2)] (Q= S, R=Ph 1 or Pr-i 2; Q=Se, R=Ph 3). Complexes 1-3 have been characterised b y X-ray crystallography. The Os-O distances in 1-3 are 1.739, 1.734 and 1.7 48 Angstrom, respectively. trans-[OsN{N(QPR(2))(2)}(2)Cl] (R=Pr-i, Q=S; R=P h, Q=Se) were obtained by reactions of [NBu4n][OsNCl4] with K[N(QPR(2))(2)] . Treatment of [OsN{N(SPPh2)(2)}(2)][BF4] with [NBu4n][OsO3N] resulted in f ormation of a mu-nitrido Os-VIII-Os-VI complex [OsN{N(SPPh2)(2)}(2)(NOsO3)] , in which the [NOsO3](-) is trans to the terminal nitride ligand. The Os-V I-N, Os-VI-N(Os) and Os-VIII-N distances are 1.617(12), 2.318(11), and 1.71 9(11) Angstrom, respectively; the Os(1)-N(4)-Os(2) angle being 159.2(7)degr ees. Treatment of [OsN{N(SPPh2)(2)}(2)][BF4] with [NBu4n][ReO4] or [NBu4n]( 2)[M6O19] gave heterometallic mu-oxo complexes trans-[OsN{N(SPPh2)(2)}(2)(O ReO3)] or trans-[{OsN[N(SPPh2)(2)](2)}(2)(M6O19)] (M=Mo or W), respectively . Reaction of [NH4](2)[OsCl6] with K[N(SPPh2)(2)] in the presence of PPh3 o r treatment of 3 with C6F5SH led to isolation of the osmium(III) homoleptic complexes [Os{N(SPR2)(2)}(3)] (R=Pr-i or Ph). The geometry around Os in th e latter is pseudo octahedral, and the average S-Os-S angle and average Os- S distance are 96.06(5)degrees and 2.450 Angstrom, respectively. Osmium(III ) phosphoraniminate complexes [Os(NPMePh2)(PMePh2){N(SPPh2)(2)}(2)] and tra ns-[Os(NPPh3)(PPh3){N(SePPh2)(2)}(2)] were prepared by the respective nitri doosmium(VI) complex with PMePh2 or PPh3. Reaction of complex 1 or 2 with h ydrazine hydrate afforded air-sensitive osmium(II) dinitrogen species, pres umably [Os{N(SPR2)(2)}(2)(N-2)] (R=Ph or Pr-i), which exhibit IR nu(N-2) at 2060 and 2040 cm(-1), respectively.