Formate (IUPAC name: methanoate) is the conjugate baseofformic acid. Formate is an anion (HCO−2) or its derivatives such as esterofformic acid. The salts and esters are generally colorless.[1]
| |||
| |||
| Names | |||
|---|---|---|---|
| Preferred IUPAC name
Formate | |||
| Systematic IUPAC name
Methanoate | |||
| Other names
Formylate | |||
| Identifiers | |||
| |||
3D model (JSmol) |
|||
| ChemSpider |
| ||
| MeSH | Formates | ||
PubChem CID |
|||
| UNII | |||
| |||
| Properties | |||
| HCOO− orHCO− 2 | |||
| Molar mass | 45.017 g mol−1 | ||
| Conjugate acid | Formic acid | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |||
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.
Formate is a common C-1 source in living systems. It is formed from many precursors including choline, serine, and sarcosine. It provides a C-1 source in the biosynthesis of some nucleic acids. Formate (or formic acid) is invoked as a leaving group in the demethylation of some sterols.[2] These conversions are catalyzed by aromatase enzymes using O2 as the oxidant. Specific conversions include testosteronetoestradiol and androstenedionetoestrone.[3]
Formate is reversibly oxidized by the enzyme formate dehydrogenase from Desulfovibrio gigas:[4]
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 react in the presence of a strong base, such as sodium methoxide:[1]
Hydrolysis of methyl formate gives formic acid and regenerates methanol:
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.[5] Ethyl formate is found in some confectionaries.[1]
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 with reduction of the Ni2+ to finely powdered nickel metal:
Such fine powders are useful as hydrogenation catalysts.[1]
