Complexation and aromatization of α,β-unsaturated cyclic ketones by Ru(H2O)62+ and (Bz)Ru(H2O)32+: molecular structure of (η6-Tosylate)(η5-hydroxycylopentadienyl)Ru and of (η6-Tosylate)(η6-1,4-dihydroxy-2,3,5,6-tetramethylbenzene)Ru

Article abstract of DOI:10.1016/0022-328X(94)05206-Q

Ruaq²⁺(OTs)2 complexes in aqueous solution to unsaturated cyclic ketones.These aromatized on heating to ?-arene Ru complexes.Thus, with cyclohexanone the main product was Ru(η⁶-phenol)2²⁺, 4, along with some Ru(η⁶-phenol)(η⁶-OTs)⁺, 6.Similarly gave cyclopentenone in the presence of various arenes Ru(η⁵-hydroxycyclopentadienyl)(η⁶-arene)⁺.Duroquinone complexed to Ruaq²⁺ as a monoprotonated hydroquinolate in Ru(η⁶-2,3,5,6-tetramethyl-1,4-hydroquinone)(η⁶-OTs), 14.Ru(η⁵-cyclopentadienyl)(η⁶-OTs), 8, and 14 were characterized by single crystal x-ray structure analyses, data see Table 1.Whereas both ligands in 8 are planar, the, 1,4-hydroquinone ligand in 14 shows distinct bending of the COH groups. Keywords: Ruthenium; Unsaturated cyclic ketones