Formate ( IUPAC name: methanoate) is the conjugate base of

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...

. Formate is an anion () or its derivatives such as ester of

. The salts and esters are generally colorless.Werner Reutemann and Heinz Kieczka "Formic Acid" in ''Ullmann's Encyclopedia of Industrial Chemistry'' 2002, Wiley-VCH, Weinheim.

Fundamentals

When dissolved in water, formic acid converts to formate: : Formate is a planar anion. The two oxygen atoms are equivalent and bear a partial negative charge. The remaining C-H bond is not acidic.

Biochemistry

: Formate is a common C-1 source in living systems. It is formed from many precursors including choline,

serine Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − form un ...

, and sarcosine. It provides a C-1 source in the biosynthesis of some

nucleic acid Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main cl ...

s. Formate (or formic acid) is ina leaving group in the demethylation of some

sterol Sterol is an organic compound with formula , whose molecule is derived from that of gonane by replacement of a hydrogen atom in position 3 by a hydroxyl group. It is therefore an alcohol of gonane. More generally, any compounds that contain the go ...

s.. These conversions are catalyzed by aromatase enzymes using O₂ as the oxidant. Specific conversions include testosterone to estradiol and

androstenedione Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ4-dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepia ...

to estrone. Formate reversibly oxidized by the enzyme formate dehydrogenase from '' Desulfovibrio gigas'': :

Formate esters

Formate esters have the formula HCOOR (alternative way of writing formula ROC(O)H or RO₂CH). Many form spontaneously when alcohols dissolve in formic acid. The most important formate ester is methyl formate, which is produced as an intermediate en route to

Methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

and carbon monoxide react in the presence of a strong base, such as sodium methoxide: :CH3OH + CO -> HCOOCH3 Hydrolysis of methyl formate gives formic acid and regenerates methanol: :HCOOCH3 -> HCOOH + CH3OH Formic acid is used for many applications in industry. Formate esters often are fragrant or have distinctive odors. Compared to the more common acetate esters, formate esters are less commonly used commercially because they are less stable.Johannes Panten and Horst Surburg "Flavors and Fragrances, 2. Aliphatic Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2015, Wiley-VCH, Weinheim. Ethyl formate is found in some confectionaries.

Formate salts

Formate salts have the formula M(O₂CH)(H₂O)_''x''. Such salts are prone to decarboxylation. For example, hydrated nickel formate decarboxylates at about 200 °C to give finely powdered nickel metal: : Such fine powders are useful as hydrogenation catalysts.

Examples

* ethyl formate, CH₃CH₂(HCOO) * sodium formate, Na(HCOO) * potassium formate, K(HCOO) * caesium formate, Cs(HCOO); see Caesium: Petroleum exploration * methyl formate, CH₃(HCOO) *

methyl chloroformate Methyl chloroformate is the methyl ester of chloroformic acid. It is an oily colorless liquid, although aged samples appear yellow. It is also known for its pungent odor. Preparation Methyl chloroformate can be synthesized using methanol and p ...

, CH₃OCOCl * triethyl orthoformate * trimethyl orthoformate, C₄H₁₀O₃ *

phenyl formate In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...

HCOOC₆H₅ * amyl formate

References

{{Reflist Carboxylate anions de:Formiate