formates

Formates are chemical derivatives of formic acid (HCOOH), including the formate ion, HCOO−, and salts such as sodium formate (HCOONa) and ammonium formate (HCOONH4). They also include formate esters, the esters of formic acid with alcohols, which have the general formula HCOO–R'. Common examples are methyl formate (HCOOCH3).

The formate ion is planar and resonance-stabilized, with the negative charge delocalized over the two oxygen atoms. Formic acid has a pKa of about 3.75, making formate a weak base. Salts of formate are typically soluble in water and often behave as buffers in aqueous solutions. Formate esters are neutral organic compounds with a carbonyl–oxygen linkage.

Formates are prepared by neutralizing formic acid with bases or by esterification of formic acid with alcohols. In nature, formate occurs as an intermediate in one-carbon metabolism and can be produced by certain bacteria and plants during anaerobic respiration.

Industrial and practical uses include sodium formate as a de-icer and buffering agent; ammonium formate is used as a buffering agent in chromatography and as a hydrogen source in some catalytic processes. Methyl formate and other formate esters serve as solvents in coatings, cleaners, and flavor or fragrance applications.

Safety: Formic acid and formates can be corrosive and toxic at high concentrations. Adequate ventilation, personal protective equipment, and adherence to handling guidelines are recommended when working with these substances.