Complexes of the platinum metals. Part 33. Synthesis of some ruthenium and osmium sulphonate derivatives: X-ray crystal structure of aqua(carbonyl)bis(toluene-p-sulphonato)bis(triphenylphosphine)ruthenium(II)
Abstract
Sulphonic acids RSO3H (R = CH3, CF3, or C6H4CH3-p) react with the precursors [MH2(CO)(PPh3)3](M = Ru or Os) and [Ru(CO)3(PPh3)2] or [OsH2(CO)2(PPh3)2] in refluxing benzene or toluene to afford the complexes [M(O3SR)2(H2O)(CO)(PPh3)2] and [M(O3SR)2(CO)2(PPh3)2] respectively. The precursors [RuH2(PPh3)4] and [OsH4(PPh3)3] react with sulphonic acids in refluxing benzene to give the η6-benzene complexes [MH(η6-C6H6)(PPh3)2][O3SR]. However a similar reaction in refluxing ethanol yielded [OsH3(PPh3)4][O3SCF3]. The complexes [Ru(O3SR)2(H2O)(CO)(PPh3)2] have been shown by variable-temperature 1H and 31P-{1H} n.m.r. spectroscopy to be fluxional in solution. The solid-state structure of one example, [Ru(O3SC6H4CH3-p)2(H2O)(CO)(PPh3)2] has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/n, with a= 24.382(5), b= 18.075(4), c= 10.729(2)Å, β= 99.03(2)°, and Z= 4. The octahedral ruthenium(II) complex contains monodentate sulphonate ligands (trans to PPh3 and CO) and an aqua ligand (trans to PPh3) with strong hydrogen-bonding interactions between the H atoms of the H2O and the non-co-ordinated oxygen atoms of the sulphonate ligands. The molecular structure is very similar to that previously reported for the alcohol dehydrogenation catalyst [Ru(O2CCF3)2(CH3OH)(CO)(PPh3)2].