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

Reactions of [Ru(PPh3)3Cl2], [Ru(CO)2Cl2]x, or [Ru(dmso)4Cl2] (dmso = dimethyl sulfoxide) with KLR[LR= N(SPR2)2, R = Ph or Pri] afforded [Ru(LR)2(PPh3)] (R = Ph 1 or Pri2), cis-[Ru(LR)2(CO)2] (L = Ph 3 or Pri4), or cis-[Ru(LPh)2(dmso)2] 5, respectively. The crystal structures of complexes 1 and 2 have been determined. They show weak agostic interaction between Ru and LRwith 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 ButNC afforded trans-[Ru(LPr)2(ButNC)2] 6, the average Ru-S and Ru-C distances of which are 2.453 and 1.990(3) Å, respectively. Reaction of RuCl3with KLRin methanol gave the homoleptic complexes [Ru(LR)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(LPh)2(PPh3)(py)] 9, reaction of 2 with py led to isolation of structurally characterised [Ru(LPr)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 SO2afforded structurally characterised cis-[Ru(LPh)2(PPh3)(SO2)] 11. The SO2ligand 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 SO2to give the μ-sulfato-bridged ruthenium(in) dimer [{Ru(LPr)(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.