Synthesis and structure of trans-dimethylammonium bis(oxalato)diaquaruthenate(III) tetrahydrate

Trans-Dimethylammonium bis(oxalato)diaquaruthenate(III) tetrahydrate, trans -[(CH3)(2)NH2][Ru(C2O4)(2)(H2O). 4H(2)O, was synthesized by diffusion of di methylamine (from dimethylformamide) into a refluxed aqueous solution of di ruthenium(II,III) tetraacetate and oxalic acid. The structure of the comple x was determined by X-ray diffraction. The Ru-O (oxalate) and Ru-O (water) distances are 2.041(3) and 1.994(3) Angstrom, respectively and the oxalate bite angle is 80.6(2)degrees. The complex displays an intricate pattern of inter- and intra-chain hydrogen bonding involving the axial water molecules , the water molecules of hydration, the dimethylammonium cation, and the ca rbonyl and carboxyl oxygens of the oxalate groups. Additional characterizat ion using infrared and UV-Vis spectroscopies, magnetic susceptibility (isot hermal and variable temperature), and cyclic voltammetry is also reported. (C) 2000 Elsevier Science S.A. All rights reserved.