Syntheses, Structures, and Properties of Mono- and Dinuclear Acetylacetonato Ruthenium(III) Complexes with Chlorido or Thiocyanato Ligands

Nakashima, Kai; Hayami, Chihiro; Nakashima, Shino; Akashi, Haruo; Mikuriya, Masahiro ; Handa, Makoto

The mononuclear and dinuclear ruthenium(III) complexes trans-Ph4P[RuIII(acac)2Cl2] (1), Ph4P[{RuIII(acac)Cl}2(μ-Cl)3] (2) and trans-Ph4P[RuIII(acac)2(NCS)2]·0.5C6H14 (3·0.5C6H14) were synthesized. Single crystals of 1, 2·H2O and 3·CH3CN suitable for X-ray crystal structure analyses were obtained through recrystallization from DMF for 1 and 2·H2O and from acetonitrile for 3·CH3CN. An octahedral Ru with bis-chelate-acac ligands and axial chlorido or κ-N-thiocyanido ligands (for 1 and 3·CH3CN) and triply μ-chlorido-bridged dinuclear Ru2 for 2·H2O were confirmed through the structure analyses. The Ru-Ru distance of 2.6661(2) of 2·H2O is indicative of the existence of the direct metal-metal interaction. The room temperature magnetic moments (μeff) are 2.00 and 1.93 μB for 1 and 3·0.5C6H14, resp., and 0.66 μB for 2. The temperature-dependent (2-300 K) magnetic susceptibility showed that the strong antiferromagnetic interaction (J ≤ -800 cm-1) is operative between the ruthenium(III) ions within the dinuclear core. In the 1H NMR spectra measured in CDCl3 at 298 K, the dinuclear complex 2 showed signals for the acac ligand protons at 2.50 and 2.39 ppm (for CH3) and 5.93 ppm (for CH), resp., while 1 and 3·0.5C6H14 showed signals with large paramagnetic shifts; -17.59 ppm (for CH3) and -57.01 ppm (for CH) for 1 and -16.89 and -17.36 ppm (for CH3) and -53.67 and -55.53 ppm (for CH) for 3·0.5C6H14. Cyclic voltammograms in CH2Cl2 with an electrolyte of nBu4N(ClO4) showed the RuIII → RuIV redox wave at 0.23 V (vs. Fc/Fc+) for 1 and the RuIII → RuII waves at -1.39 V for 1 and -1.25 V for 3·0.5C6H14 and the RuIII-RuIII → RuIII-RuIV and RuIII-RuIII → RuIII-RuIV waves at 0.91 V and -0.79 V for 2.

Magnetochemistry

MDPI

10

3

https://doi.org/10.3390/magnetochemistry10030016

https://doi.org/10.3390/magnetochemistry10030016