Abstract
The oxo-centered, trinuclear, mixed valence [[Ru-3((II,III,III))(mu(3)-O) (mu-CH3CO2)(6)(H2O)(3)]center dot 2H(2)O (2) acetate complex has been prepared with high yield through reduction of [(Ru3O)-O-(III,III,III)(CH3CO2)(6)(CH3OH)(3)]center dot CH3CO2 precursor compound in presence of muccic acid under hydrothermal conditions. The crystalline trinuclear oxo-cluster has been obtained as crystalline powder and characterized by single-crystal and powder X-ray diffraction, elemental analysis, SEM, TGA, IR spectroscopy. Complex 2 composes of mu(3)-oxocentered trinuclear ruthenium array and exhibits the oxidation state delocalization between three Ru atoms at 293 K. Accurate single-crystal analysis along with valence bond calculations reveal trapped-valence state delocalization at room temperature, whereas three-site relaxation occurs at 100 K leading to Ru(II) and Ru-2(III) formal states. Moreover, the mixed valence of (RuRu2III)-Ru-II unit in compound 2 has been confirmed by XANES spectroscopy. The catalytic behavior of oxo-centered triruthenium complex 2 has been examined in hydration of nitriles and isomerization of allylic alcohols reactions both realized in aqueous media. (C) 2016 Elsevier B.V. All rights reserved.