Controlling the electronic density of the [Ru 2(DPhF) 3(O 2CR)] + core to obtain one-dimensional compounds

Abstract

The substitution of the acetate ligand in [Ru 2Cl(DPhF) 3(O 2CMe)] (DPhF − = N,N′-diphenylformamidinate) by the pentafluorobenzoate group gives the complex [Ru 2Cl(DPhF) 3(O 2CC 6F 5)(OH 2)] ( 1), and the reaction of 1 with AgSO 3CF 3 leads to the compound [Ru 2(DPhF) 3(O 2CC 6F 5)(OH 2) 2]SO 3CF 3 ( 2). The low donor character of the pentafluorobenzoate ligand compared to the acetate group decreases the electron density of the Ru 2 5+ unit which permits ligands to bond at both axial positions of the diruthenium moiety. The use of the [Au(CN) 2] − group yields the new complex {[Ru 2(DPhF) 3(O 2CC 6F 5)][Au(CN) 2]} ( 3). Complexes 1– 3 are characterized by elemental analysis, 19F{ 1H} NMR, IR and electronic spectroscopy, mass spectrometry and variable-temperature magnetic measurements. The crystal structure of 2·H 2O is also reported. The magnetic properties of complex 1 is in accordance with the ground-state configuration σ 2 π 4 δ 2( π* δ*) 3. In contrast, the slope of representation of the magnetic moment towards temperature in complex 2 indicates a gradual transition from essentially high spin ( S = 3/2) to low spin ( S = 1/2) configuration.