alcoholates

Alcoholates are salts containing the alkoxide anion RO− bound to a metal cation, M+. They are the deprotonated forms of alcohols and are commonly encountered as sodium alkoxides such as sodium methoxide (NaOCH3) and sodium ethoxide (NaOEt), as well as bulkier bases like potassium tert-butoxide (KOtBu) or lithium tert-butoxide (LiOtBu).

Preparation is typically by deprotonating an alcohol with a strong base (for example NaH, Na, or KOtBu), though alkoxides can also be formed by salt exchange with a metal alkoxide and a metal salt under suitable conditions.

They are strong bases and good nucleophiles in SN2 reactions, particularly in aprotic solvents, and they behave as weak nucleophiles in protic media due to solvation. They readily react with water to form the corresponding alcohol and metal hydroxide, and they are moisture- and air-sensitive.

Common uses include serving as bases and nucleophiles in Williamson ether synthesis, transesterification reactions (for example in biodiesel production using methoxide or ethoxide catalysts), and as precursors in sol-gel chemistry to prepare metal oxides (such as titanium isopropoxide Ti(OiPr)4).

Safety considerations include their caustic and moisture-sensitive nature. They react violently with water and can release heat; they should be handled under inert atmosphere or with dry solvents, and appropriate protective equipment used.