Organometallic thiol and thiolato complexes of ruthenium(IV)

Abstract

Reaction of the ruthenium(IV) chloro-bridged dimer [{Ru(η³:η³-C₁₀H₁₆)Cl(µ-Cl)}₂]1 with a range of alkane- and arene-thiols in CH₂Cl₂ resulted in the formation of the simple, bridge-cleaved adducts [Ru(η³:η³-C₁₀H₁₆)Cl₂(HSR)](R = Et 2, Me 3, Prⁱ4, Bu^t5 or Ph 6). Reaction of 1 with an excess of thiol in methanol gave doubly thiolate-bridged compounds [{Ru(η³:η³-C₁₀H₁₆)Cl(µ-SR)}₂](R = Et 7, Ph 12 or C₆F₅13) each of which exists as two diastereoisomers but as a single geometrical isomer. In the case of 7 and 12 separation of the two diastereomeric forms proved possible because of their remarkably different solubilities in methanol, and their kinetic inertness. Reactions of 2 and 3 with 1 gave the mixed-bridge chloro/thiolato complexes [{Ru(η³:η³-C₁₀H₁₆)Cl}₂(µ-Cl)(µ-SR)](R = Me 9 or Et 8). The unusual stereochemistry of these compounds is evident from analysis of their variable-temperature ¹H NMR spectra. The crystal structure of 8 has been determined. Reaction of 1 with H₂S in CH₂Cl₂ proceeds via the H₂S adduct [Ru(η³:η³-C₁₀H₁₆)Cl₂(SH₂)]10, which rapidly reacts with further 1 with accompanying loss of HCl to give the singly SH-bridged complex [{Ru(η³:η³-C₁₀H₁₆)Cl}₂(µ-Cl)(µ-SH)]11. Reaction of the EtSH compound 2 with a range of Ru^II and Rh^III-containing compounds enabled the isolation of a number of unusual mixed-valence and mixed-metal complexes containing one or two bridging ethanethiolate ligands. The ruthenium(IV)–rhodium(III) compounds [(η³:η³-C₁₀H₁₆)ClRu(µ-Cl)(µ-SEt)RhCl(η⁵-C₅Me₅)] and [(η³:η₃-C₁₀H₁₆)ClRu(η-SEt)₂RhCl₂(PMe₂Ph)₂] have been characterised by X-ray crystallography.