Search Results (2)

By using [Ru₂(O₂CC₃H₇)₄Cl]_n (1) as a starting material, ⁿBu₄N[Ru₂(O₂CC₃H₇)₄Cl₂] (ⁿBu₄N⁺ = tetra(n-butyl)ammonium cation) (2) and [Ru₂(O₂CC₃H₇)₄(H₂O)₂]BF₄ (3) were prepared. The lantern-type dinuclear structures with axial chloride ions or water molecules were confirmed for 2 and 3 by X-ray crystal structure analyses. The crystal structures of 2 and 3 were compared with that of 1. In the crystal of 2, there were three crystallographically different dinuclear units; the Ru–Ru distances of each unit were 2.3094(3), 2.3046(4), and 2.3034(4) Å, respectively, which were longer than those of 1 (2.281(4) Å) and 3 (2.2584 (7) Å). Temperature dependent magnetic susceptibility measurements were performed for 1 and 2 as well as 3. The effective magnetic moments (µ_eff) at 300 K were 3.97 (for 1), 4.00 (for 2), and 3.97 µ_B (for 3), respectively. The decreases in the µ_eff value were confirmed for all of the complexes due to the large zero-field splitting (D): D = 68 cm⁻¹ for 1, 78 cm⁻¹ for 2, and 60 cm⁻¹ for 3. Cyclic voltammograms measured in CH₂Cl₂ with a electrolyte of ⁿBu₄N(BF₄) showed the Ru₂⁵⁺/Ru₂⁴⁺ process at −0.2–−0.4 V (vs. SCE) and the Ru₂⁶⁺/Ru₂⁵⁺ one at 1.3–1.4 V (vs. SCE), of which potentials were confirmed by the DFT calculation for ⁿBu₄N[Ru₂(O₂CC₃H₇)₄Cl₂]. Full article

A lantern-type diruthenium(II,III) complex [Ru₂(HNOCPh)₄(BF₄)(H₂O)] was prepared from [Ru₂(HNOCPh)₄Cl]_n by removal of the axial chlorido-bridge using AgBF₄ in THF. The room temperature magnetic moment (per Ru₂⁵⁺ unit) of [Ru₂(HNOCPh)₄(BF₄)(H₂O)] is 3.84 μ_B, which is similar to that (4.15 μ_B) of [Ru₂(HNOCPh)₄Cl]_n, for which magnetic measurement was newly performed in this study. These results indicate that both of the complexes have a spin state of S = 3/2, although temperature-variable (VT) magnetic moments (2–300 K) showed that considerable antiferromagnetic interaction (zJ = −2.8 cm⁻¹) exists through the axial chlorido-bridge for [Ru₂(HNOCPh)₄Cl]_n, but such a large interaction (zJ = −0.08 cm⁻¹) does not exist for [Ru₂(HNOCPh)₄(BF₄)(H₂O)], where the large zero-field splitting D = 61 cm⁻¹ is operative for both complexes, like other lantern-type diruthenium(II,III) complexes. The X-ray single-crystal structure analysis of [Ru₂(HNOCPh)₄(BF₄)(H₂O)]·2(acetone) showed that the axial positions of the complex were occupied by a fluorine atom of the BF₄⁻ ion and an oxygen atom of the water molecule, with distances of Ru-F_ax = 2.3265(19) Å and Ru-O_ax = 2.280(2) Å, respectively. The Ru-Ru bond distance was 2.2793(4) Å, which is shorter than those (2.295(2) and 2.290(2) Å) reported for [Ru₂(HNOCPh)₄Cl]_n. The quartet ground states (S = 3/2) were reasonably interpreted for [Ru₂(HNOCPh)₄(BF₄)(H₂O)] and [Ru₂(HNOCPh)₄Cl]_n, as well as the theoretically modeled complex cation [Ru₂(HNOCPh)₄]⁺, by DFT calculation results. A Ru₂⁶⁺/Ru₂⁵⁺ redox couple was observed at 1.12 V (vs. SCE) for [Ru₂(HNOCPh)₄(BF₄)(H₂O)] in dichloromethane containing Bu₄NPF₆ as electrolyte. Full article