Dioxo- and nitrido-osmium complexes with imidodiphosphinochalcogenido ligands [N(QPR2)2]- (Q = S or Se; R = Ph or Pri)

Abstract

Reactions of trans-K2[OsVIO2(OH)4] with 2 equivalents of HN(QPR2)2 yielded the dioxoosmium(VI) complexes trans-[OsO2{N(QPR2)2}2] (Q = S, R = Ph 1 or Pri2; Q = Se, R = Ph 3). Complexes 1–3 have been characterised by X-ray crystallography. The Os–O distances in 1–3 are 1.739, 1.734 and 1.748 Å, respectively. trans-[OsN{N(QPR2)2}2Cl] (R = Pri, Q = S; R = Ph, Q = Se) were obtained by reactions of [NBu4n][OsNCl4] with K[N(QPR2)2]. Treatment of [OsN{N(SPPh2)2}2][BF4] with [NBu4n][OsO3N] resulted in formation of a μ-nitrido OsVIII–OsVI complex [OsN{N(SPPh2)2}2(NOsO3)], in which the [NOsO3]− is trans to the terminal nitride ligand. The OsVI–N, OsVI–N(Os) and OsVIII–N distances are 1.617(12), 2.318(11), and 1.719(11) Å, respectively; the Os(1)–N(4)–Os(2) angle being 159.2(7)°. Treatment of [OsN{N(SPPh2)2}2][BF4] with [NBu4n][ReO4] or [NBu4n]2[M6O19] gave heterometallic μ-oxo complexes trans-[OsN{N(SPPh2)2}2(OReO3)] 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 or treatment of 3 with C6F5SH led to isolation of the osmium(III) homoleptic complexes [Os{N(SPR2)2}3] (R = Pri or Ph). The geometry around Os in the latter is pseudo octahedral, and the average S–Os–S angle and average Os–S distance are 96.06(5)° and 2.450 Å, respectively. Osmium(III) phosphoraniminate complexes [Os(NPMePh2)(PMePh2){N(SPPh2)2}2] and trans-[Os(NPPh3)(PPh3){N(SePPh2)2}2] were prepared by the respective nitridoosmium(VI) complex with PMePh2 or PPh3. Reaction of complex 1 or 2 with hydrazine hydrate afforded air-sensitive osmium(II) dinitrogen species, presumably [Os{N(SPR2)2}2(N2)] (R = Ph or Pri), which exhibit IR ν(N2) at 2060 and 2040 cm−1, respectively.