Ruthenium complexes with N(SPR2)2− (R = Ph or Pri)

Abstract

Reactions of [Ru(PPh₃)₃Cl₂], [Ru(CO)₂Cl₂]_x, or [Ru(dmso)₄Cl₂] (dmso = dimethyl sulfoxide) with KL^R [L^R = N(SPR₂)₂, R = Ph or Prⁱ] afforded [Ru(L^R)₂(PPh₃)] (R = Ph 1 or Prⁱ2), cis-[Ru(L^R)₂(CO)₂] (L = Ph 3 or Prⁱ4), or cis-[Ru(L^Ph)₂(dmso)₂] 5, respectively. The crystal structures of complexes 1 and 2 have been determined. They show weak agostic interaction between Ru and L^R with calculated Ru⋯H–C separations of 3.37 and 2.91 Å, respectively. The Ru–P and average Ru–S distances in 1 are 2.218(1) and 2.400 Å, respectively. The corresponding bond lengths for 2 are 2.210(2) and 2.404 Å. Treatment of 2 with Bu^tNC afforded trans-[Ru(L^Pr)₂(Bu^tNC)₂] 6, the average Ru–S and Ru–C distances of which are 2.453 and 1.990(3) Å, respectively. Reaction of RuCl₃ with KL^R in methanol gave the homoleptic complexes [Ru(L^R)₃] (L = Ph 7 or Prⁱ8). The average Ru–S distance and S–Ru–S angle in 7 are 2.414 Å and 97.41°, respectively. While complex 1 reacts with pyridine (py) to give [Ru(L^Ph)₂(PPh₃)(py)] 9, reaction of 2 with py led to isolation of structurally characterised [Ru(L^Pr)₂(SO)] 10. The Ru–S(O) and S–O bond lengths in 10 are 2.0563(11) and 1.447(3) Å, respectively, the Ru–S–O angle being 125.5(2)°. Treatment of 1 with SO₂ afforded structurally characterised cis-[Ru(L^Ph)₂(PPh₃)(SO₂)] 11. The SO₂ ligand binds to Ru in 11 in a η¹-S mode and the Ru–S(O) distance is 2.140(4) Å. Complex 2 reacted with SO₂ to give the μ-sulfato-bridged ruthenium(III) dimer [{Ru(L^Pr)(PPh₃)}₂(μ-SO₄)₂] 12, which has been characterised by X-ray crystallography. The Ru–P and average Ru–S and Ru–O distances in 12 are 2.294(2), 2.321 and 2.133 Å, respectively. Complex 1 is capable of catalysing hydrogenation of styrene in the presence of Et₃N presumably via a ruthenium hydride intermediate.