摘要:
                                The reaction of H-2[OsBr6] with DMSO in ethanol solution resulted in DMSO complex [H(dmso-O)(2)][Os-III(dmso-S)(2)Br-4] (1) described previously as an intermediate product in the reaction of K-2[OsBr6] with DMSO and characterized by EAS and ESR spectra. The coordination of DMSO molecules was established by IR and H-1 and C-13 NMR spectroscopy. The oxidation state of osmium and trans arrangement of DMSO molecules in the anion were established by ESR. The behavior of complex 1 in solutions was studied by EAS, ESR, and mass-spectrometry: a displacement of Br- ions accompanied by the reduction of osmium to oxidation state +2 occurs in DMSO, a solvation with displacement of DMSO molecules is observed at the first stage in water and methanol (rate constants 2.3 x 10(-4) and 1.7 x 10(-3) s(-1), respectively), the sequential substitution of DMSO molecules and osmium oxidation to form [(OsBr6)-Br-IV](2-) ions takes place in 4 mol/L HBr.