Vanadium-lithium alkoxides: synthesis, structure, spectroscopic characterisation and accidental degradation of silicone grease

two complexes containing both vanadium and lithium, [v6li10o8(onep)14{o2si(me)2(onep)}2] (1) and [v(onep)3(μ-onep)2li(thf)2] (2), nep = neopentyl, me = methyl and thf = tetrahydrofuran, have been isolated in high yield and characterised by a number of techniques including x-band electron paramagnetic resonance (epr) and 29si{1h} nuclear magnetic resonance (nmr) spectroscopies, magnetic susceptibility measurements and single crystal x-ray diffractometry. despite the similar preparation conditions, the two products present remarkably distinctive structural features: complex 2is a binuclear adduct of "v(onep)4" and "li(onep)(thf)2", while 1is a mixed-valence, 16-metal aggregate. the large molecular oxoalkoxide 1also contains silanolate units, {osi(me2)(onep)} -, produced by nucleophilic attack of neopentoxide groups on si-o bonds of silicone grease accidentally dissolved in the reaction media. both products have promising applications in organic and inorganic synthesis, including the preparation of uncommon v-li and/or si containing oxides.