Reduction of dichlorotris(triphenylphosphine)ruthenium(II) in the presence of acetonitrile, pyridine, 2,2′-bipyridyl, and styrene

摘要: The reduction of dichlorotris(triphenylphosphine)ruthenium(II) in tetrahydrofuran–acetonitrile by sodium or magnesium amalgam produces a compound shown to be hydrido ortho-metallated phosphine ruthenium(II) complex RuH(C6H4PPh2)(MeCN)(PPh3)2. This has all the characteristics previously reported and alleged ruthenium(0) containing π-bonded acetonitrile ‘Ru(MeCN)(PPh3)4·MeCN’.Detailed study system shows that there are labile intermediates, Ru(MeCN)2(PPh3)2 which is paramagnetic, Ru(MeCN)3(PPh3)2, Ru(MeCN)(PPh3)3. pyridine gives two isomers RuH(C6H4PPh2)(C5H5N)(PPh3)2 while presence 2,2′-bipyridyl main product purple RuH(C6H4PPh2)(bipy)(PPh3). In styrene known Ru(styrene)2(PPh3)2 obtained.Reactions species RuH(C6H4PPh2)(MeCN)(PPh3)2 with propene water reported.The various compounds have been characterised i.r. 1H 31P n.m.r. spectroscopy.It concluded reductions RuCl2(PPh3)3 4 lead abstraction hydride from solvent if no strongly co-ordinating ligand present. ligands, triphenylphosphine groups formed via intramolecular oxidative addition C–H bond transient intermediates.