(η6-Arene)ruthenium oxomolybdenum and oxotungsten clusters. Stereochemical non-rigidity of [{Ru(η6-p-MeC6H4Pr i)}4Mo4O16] and crystal structure of [{Ru(η6-p-MeC6H4Pr i)}4W2O10]

Abstract

According to a multinuclear NMR study, the cluster [{Ru(η⁶-p-MeC₆H₄Pr ⁱ)}₄Mo₄O₁₆] exists as two isomers, the windmill-like form and the triple-cubane form, which are in equilibrium in solution, while the tungsten analogue, which has been obtained together with the double-cubane type cluster [{Ru(η⁶-p-MeC₆H₄Pr ⁱ)}₄W₂O₁₀] by reaction of [{Ru(η⁶-p-MeC₆H₄Pr ⁱ)Cl₂}₂] with (NBuⁿ₄)₂[WO₄] in acetonitrile, only displays the windmill-like structure.