Arene ruthenium bis-saccharinato complexes: Synthesis, molecular structure and catalytic oxidation properties in aqueous solution

Arene ruthenium complexes [(eta(6)-arene)Ru(sacc)(2)(OH2)] (arene - para-cymeme, benzene) containing an aqua and two saccharinato ligands have been synthesized from [(eta(6)-arene) RuCl2](2) and sodium saccharinate in a water-ethanol mixture (1:1). The aqua complex [(eta(6)-MeC6H4Pri)Ru(sacc)(2)(OH2)] reacts with acetonitrile to give the acetonitrile complex [(eta(6)-MeC6H4Pri)Ru(sacc)(2)(NCMe)]. The corresponding benzene derivative [(eta(6)-C6H6) Ru(sacc)(2)(NCMe)] was obtained from [(eta(6)-C6H6)RuCl2](2) and saccNa in an acetonitrile-methanol mixture (1:1). All new complexes show a piano-stool geometry with two monohapto nitrogen-bonded saccharinato ligands in addition to a H2O or MeCN ligand. All complexes of the type [(eta(6)-arene) Ru(sacc)(2)(OH2)] and [(eta(6)-arene) Ru(sacc)(2)(NCMe)] were found to catalyze the oxidation of secondary alcohols with tert-butyl hydroperoxide ((BuOOH)-O-t) to give the corresponding ketones in aqueous solution. (C) 2011 Elsevier B. V. All rights reserved.