Metallalkoxider

Metallalkoxider, or metal alkoxides, are a class of inorganic–organic compounds that feature metal–oxygen–alkyl bonds. Their general formula is M(OR)n, where M denotes a metal cation and OR is an alkoxide group. They are typically colorless liquids or solids and many are sensitive to air or moisture, reacting with water to form metal–oxygen networks and alcohol as a byproduct.

Preparation and chemistry: Metal alkoxides can be prepared by transesterification reactions between metal alkoxides and alcohols, by salt metathesis of metal halides with alkoxide reagents, or by direct alkoxide substitution on suitable metal precursors. In the presence of water, they undergo hydrolysis and condensation to form M–O–M linkages, which leads to the formation of metal oxides. In solution, they can form oligomeric or polymeric species, enabling controlled hydrolysis in sol–gel processes.

Applications: These compounds are widely used as precursors to metal oxides in sol–gel chemistry, enabling the synthesis of TiO2, Al2O3, ZrO2, SiO2 and related materials at relatively low temperatures. They serve as catalysts and catalyst supports, coatings and thin films, and in the preparation of ceramic powders and hybrid materials.

Examples: Common representatives include titanium tetraisopropoxide Ti(OiPr)4, aluminum isopropoxide Al(OiPr)3, tin tetrakis(alkoxide) Sn(OR)4, and zirconium methoxide Zr(OMe)4. Safety notes: Many metallalkoxider are moisture sensitive and react with water to release alcohols; some are flammable or corrosive and should be handled under appropriate conditions.