A trinuclear ruthenium(II) complex with rare S,O-bridging sulfoxide ligands

Abstract

The trimetallic compound [Ru₃(µ-mpso-S,O)₂(µ-Cl)₄(mpso-S)₄Cl₂] (mpso = C₇H₈OS, methyl phenyl sulfoxide) 1 was prepared from hydrated RuCl₃ and methyl phenyl sulfoxide. A crystal structure determination revealed a linearly arranged molecule with three ruthenium atoms in distorted octahedral configurations with bridging chloro and S,O-mpso ligands. For the ruthenium metals with triply bridged chloro ligands, the Ru–Cl–Ru angles are 81.8(4), 82.7(1) and 83.2(1)°, and the Ru· · ·Ru non-bonded distance is 3.218 Å. In contrast, the Ru–Cl–Ru angle on the bridging mpso part of the molecule is 100.7(1)°, and the Ru· · ·Ru non-bonded distance is 3.686 Å. The configuration at sulfur on S2, S4 and S5 is opposite to that at S1, S3 and S6. In solution, the methyl resonances in the ¹H and ¹³C NMR spectra of 1 are found in the δ ranges 3.81–2.70 and 49.7–44.9, respectively. The methyl resonances of the S,O-bridging mpso ligands are shifted upfield in the ¹H NMR spectrum, but furthest downfield in the ¹³C NMR spectrum.