Ionic crystals based on Keggin anion and mixed-valent diruthenium tetracetate: [Ru2(CH3COO)4(H2O)2]2[HnXW12O40]•[Ru2(CH3COO)4(H2O)Cl]•12H2O (X = B, Si, Ge)

Three new ionic crystals based on Keggin anion and mixed-valent diruthenium tetracetate, [Ru-2(CH3CO2)(4)(H2O)(2)](2)[HnXW12O40]center dot[Ru-2(CH3CO2)(4)(H2O)Cl]center dot 12H(2)O {X = B, n = 3 (1); X = Si, n = 2 (2); X = Ge, n = 2 (3)}, have been prepared in acidic aqueous solution at about pH 3.0 by reaction of K4BW12O40 center dot mH(2)O, K8SiW11O39 center dot mH(2)O and K8GeW11O39 center dot mH(2)O with diruthenium tetracetate Ru-2(CH3- COO)(4)Cl, respectively, and their structures were determined by X-Ray diffraction analysis. They are isostructural structure with the ratio of heteropolytungstate anion, Ru2(CH3CO2) cation and neutral molecular Ru-2(CH3CO2)(4)Cl of 1:2:1. The cyclic voltammetry in 0.5 M KNO3 aqueous solution at pH 3.0 show the respective electrochemical behaviors of the W-centers and Ru-2-centers for these three complexes. Magnetic data analysis shows that diruthenium units display the ground state electronic configuration pi r*(2)delta* with large positive D value. (C) 2011 Elsevier Masson SAS. All rights reserved.