Formate (

IUPAC The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...

name: methanoate) is the

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

of formic acid. Formate is an

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

() or its derivatives such as

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

of formic acid. 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 Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but r ...

, serine, and

sarcosine Sarcosine, also known as ''N''-methylglycine, or monomethylglycine, is a monopeptide with the formula CH3N(H)CH2CO2H. It exists at neutral pH as the zwitterion CH3N+(H)2CH2CO2−, which can be obtained as a white, water-soluble powder. Like som ...

. It provides a C-1 source in the biosynthesis of some nucleic acids. Formate (or formic acid) is ina leaving group in the

demethylation Demethylation is the chemical process resulting in the removal of a methyl group (CH3) from a molecule. A common way of demethylation is the replacement of a methyl group by a hydrogen atom, resulting in a net loss of one carbon and two hydrogen at ...

of some sterols.. These conversions are catalyzed by

aromatase Aromatase (), also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily, which are monooxygenases that catalyze many ...

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s using O₂ as the oxidant. Specific conversions include

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...

and androstenedione to

estrone Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized ...

. Formate reversibly oxidized by the enzyme formate dehydrogenase from ''

Desulfovibrio ''Desulfovibrio'' is a genus of Gram-negative sulfate-reducing bacteria. ''Desulfovibrio'' species are commonly found in aquatic environments with high levels of organic material, as well as in water-logged soils, and form major community member ...

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 formic acid. Methanol and

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

react in the presence of a strong base, such as

sodium methoxide Sodium methoxide is the simplest sodium alkoxide. With the formula , it is a white solid, which is formed by the deprotonation of methanol. Itis a widely used reagent in industry and the laboratory. It is also a dangerously caustic base. P ...

: :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 Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organ ...

catalysts.

Examples

ethyl formate Ethyl formate is an ester formed when ethanol (an alcohol) reacts with formic acid (a carboxylic acid). Ethyl formate has the characteristic smell of rum and is also partially responsible for the flavor of raspberries. It occurs naturally in the b ...

, CH₃CH₂(HCOO) *

sodium formate Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder. Preparation For commercial use, sodium formate is produced by absorbing carbon monoxide under pressure in solid sodium hydroxide ...

, Na(HCOO) *

potassium formate Potassium formate, HCO2K, HCOOK, or CHKO2, is the potassium salt of formic acid. This strongly hygroscopic white solid is an intermediate in the formate potash process for the production of potassium. Potassium formate has also been studied as a ...

, K(HCOO) * caesium formate, Cs(HCOO); see Caesium: Petroleum exploration *

methyl formate Methyl formate, also called methyl methanoate, is the methyl ester of formic acid. The simplest example of an ester, it is a colorless liquid with an ethereal odour, high vapor pressure, and low surface tension. It is a precursor to many other co ...

, CH₃(HCOO) * methyl chloroformate, CH₃OCOCl *

triethyl orthoformate Triethyl orthoformate is an organic compound with the formula HC(OC2H5)3. This colorless volatile liquid, the orthoester of formic acid, is commercially available. The industrial synthesis is from hydrogen cyanide and ethanol. It may also be pr ...

trimethyl orthoformate Trimethyl orthoformate (TMOF) is the organic compound with the formula HC(OCH3)3. A colorless liquid, it is the simplest orthoester. It is a reagent used in organic synthesis for the formation of methyl ethers. The product of reaction of an ald ...

, C₄H₁₀O₃ * phenyl formate HCOOC₆H₅ *

amyl formate Amyl may refer to: * Amylum or starch, a carbohydrate ** Amylopectin, a polymer of glucose found in plants; one of two components of starch ** Amylose, a helical polymer made of α-D-glucose units; one of two components of starch * Pentyl, a five- ...

References

{{Reflist Carboxylate anions de:Formiate