Structural, spectroscopic and redox studies of trans-[RuX2L4](0/+) (L = PR3, AsR3 or SbR3; X = Cl, Br or I). Crystal structures of trans-[RuX2(EMe2Ph)(4)] (X = Br, E = Sb; X = I, E = As), [Ru2Br5(SbMe2Ph)(4)] and [Ru2I3(PMe2Ph)(6)][CF3SO3]

The complexes trans-[RuX2L4] (X = Cl, Br or I; L = PMe3, AsMe2Ph or SbMe2Ph) have been prepared from RuCl3 . nH(2)O, LiX and L, from [Ru(dmf)(6)][CF3SO3](3) (dmf = N,N-dimethylformamide), LiX and L, and in other ways. The complexes cis-[RuX2(PMe2Ph)(4)] (X = Cl or Pr) have been made from [RuX2(PPh3)(3)] and PMe2Ph in hexane and cis-[RuX2(PMe3)(4)] from solutions of the trans isomers on standing in CH2Cl2. Oxidation of trans-[RuX2L4] to trans[RuX2L4]BF4 has been achieved either with AgBF4 in CH2Cl2 or concentrated HNO3 in aqueous HBF4. The complexes have been characterised by analysis, UV/VIS, IR, H-1 and P-31-{H-1) NMR spectroscopy as appropriate, and the Ru-II-Ru-III oxidations probed by cyclic voltammetry. The behaviour of this series-of complexes is compared with that of the osmium [OsX2L4](0/+/2+) analogues. The crystal structures of trans-[RuX2L4] (X = I, L = AsMe2Ph; X = Br, L = SbMe2Ph), [Ru2Br5(SbMe2Ph)(4)] and [Ru2I3(PMe2Ph)(6)][CF3SO3] have been determined.