Metal oxoalkoxides. Synthesis, properties and structures

The review surveys the pathways of formation of crystalline oligomeric oxoalkoxides M mO n(OR) p, which are products of partially controlled (or uncontrolled) hydrolysis, oxidation, thermal decomposition of mono- and bimetallic alkoxides of the ortho series M(OR) n and M mM 'n(OR) p or elimination of ethers from these compounds. The physicochemical properties of oxoalkoxides (solubility, the behaviour in solutions, volatility, etc.) differ considerably from the properties of the corresponding alkoxides. Hence, oxoalkoxides can be considered as immediate precursors of oxide materials produced by sol–gel technology. The M mO n(OR) p compounds are classified according to the sizes of associates. The crystal chemistry of alkoxides is discussed. The bibliography includes 249 references.