Alkoxidsalter

Alkoxidsalter, also known as alkoxide salts, are chemical compounds that consist of an alkoxide anion (RO−) paired with a metal cation. They are most commonly encountered as metal alkoxides, with a general formula such as MOR, where M is a metal (for example sodium, potassium, or calcium) and R is an alkyl group. These salts are typically moisture sensitive and exist as solids or low‑viscosity liquids depending on the alkyl group and the metal.

Preparation and structure: Alkoxide salts can be prepared by direct reaction of a metal with an alcohol (for example, 2 Na + 2 CH3OH → 2 NaOCH3 + H2) or by salt metathesis from metal hydroxides or oxides with an alcohol. In many cases larger, more complex alkoxides are formed by reactions of metal alkoxides with additional alkyl groups or ligands. In industry, alkoxide species such as sodium methoxide and potassium tert-butoxide are among the most widely used examples.

Chemical properties and reactivity: Alkoxide salts are strong bases and good nucleophiles. They readily react with water and oxygen, hydrolyzing to alcohols and metal hydroxides or oxides. They are usually stored under inert or dry conditions to prevent hydrolysis. Their basic and nucleophilic character makes them versatile reagents in organic synthesis and catalysis.

Applications: Sodium methoxide and sodium ethoxide are common bases in organic chemistry, used for deprotonations, transesterifications, and various substitution reactions. Alkoxide salts serve as catalysts and initiators in polymerization processes, and certain alkoxides act as precursors to metal oxides used in ceramics, coatings, and catalysis. A notable industrial use is the transesterification of triglycerides with methanol to produce biodiesel, where metal alkoxides act as catalysts.

Safety and handling: These salts are caustic and reactive toward moisture, releasing alcohols and hydroxides. They require dry handling, appropriate personal protective equipment, and storage under inert atmosphere or in dry, sealed containers.