En route to {Mo2O2(μ2-O)2}2+ species: Isolation and structural characterization of a novel methoxide-bridged Mo(V) complex

Reaction of a mononuclear [MoOCl4(H2O)]− with pyridinium acetate in methanol leads to formation of an unusual complex, (PyH)2[Mo2O3(OMe)(OOCCH3)Cl4]. Instead of the common dioxide-bridged structure, the anionic complex features a pair of metal centres bridged by oxide, methoxide and acetate. The Mo−Mo bond distance is 2.6390(2) Å. The intermediate nature of this triply-bridged species was shown by its reactions with pyridine and methanol which afforded stable {Mo2O2(μ2-O)2}2+ species.