Synthesis and characterization of a monoruthenium(III)-substituted Dawson polyoxotungstate derived by Br-2 oxidation of the 1 : 2 complex of ruthenium(II) and [alpha(2)-P2W17O61](10-). The reactivity of cis-[RuCl2(DMSO)(4)] as a ruthenium source

Synthesis and characterization of the monoruthenium(III)-substituted Dawson polyoxotungstate K-7[alpha (2)-P2W17O61RuIII(H2O)]. 19H(2)O 2, expected to be an effective homogeneous oxidation catalyst precursor, is described. The reaction products of cis-[(RuCl2)-Cl-II(DMSO)(4)] as the ruthenium source with mono-lacunary Dawson polyoxotungstate have been examined. By 5 h reaction of cis-[(RuCl2)-Cl-II(DMSO)(4)] with K-10[alpha (2)-P2W17O61] in ice-cooled, HCl-acidic aqueous solution, a water-soluble 1:2-type diamagnetic ruthenium(II) complex, with formula K-18[Ru-II(DMSO)(2)(P2W17O61)(2)]. 35H(2)O 1, was unexpectedly obtained as an analytically pure, homogeneous tan-colored solid, in which two DMSO molecules are coordinated to the ruthenium(II) atom. By Br-2 oxidation of 1, the 1:1-type paramagnetic complex 2 was obtained as a black crystalline solid. Characterization of 1 and 2 has been carried out with complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), FT-IR, magnetic susceptibility measurements, cyclic voltammetry, UV-vis absorption and P-31 and W-183 NMR spectroscopies, as well as H-1 and C-13 NMR for 1.