Editing Formate

{{Short description|Salt or ester of formic acid}}
{{Chembox
| ImageFile1 =Formate.svg
| ImageFile1_Ref = {{chemboximage|correct|??}}
| ImageSize1 = 200
| ImageName1 = Stereo skeletal formula of formate
| ImageFileL1 = Formate-3D-balls.png
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageNameL1 = Aromatic ball and stick model of formate
| ImageFileR1 = Formate-3D-vdW.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageNameR1 = Space-filling model of formate
| PIN = Formate
| SystematicName = Methanoate
| OtherNames = Formylate<br/>Methylate<br/>Isocarbonite<br/>Carbonite(1-)<br/>Hydrogencarboxylate<br/>Metacarbonoate<br/>Oxocarbinate<br/>Oxomethyl oxide ion<br/>Oxomethoxide
|Section1={{Chembox Identifiers
| CASNo = 71-47-6
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 283
| ChemSpiderID = 277
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| MeSHName = Formates
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 
| ChEMBL =
| ChEMBL_Ref =
| Beilstein =
| Gmelin =
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0YIW783RG1
| SMILES = O=C[O-]
| StdInChI = 
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = 
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| Formula = {{chem|HCOO|−}} or {{chem|HCO|2|-}}
| ConjugateAcid = [[Formic acid]]
| MolarMass = 45.017 g mol<sup>−1</sup>
}}
}}

'''Formate''' ([[IUPAC]] name: '''methanoate''') is the [[conjugate base]] of [[formic acid]].  Formate is an [[anion]] ({{chem2|HCO2-}}) or its derivatives such as [[ester]] of [[formic acid]].  The salts and esters are generally colorless.<ref name=Ullmann_2009>{{citation | doi = 10.1002/14356007.a12_013 | chapter = Formic Acid | title = Ullmann's Encyclopedia of Industrial Chemistry | date = 2000 | last1 = Reutemann | first1 = Werner | last2 = Kieczka | first2 = Heinz | isbn = 3-527-30673-0 }}</ref>  

==Fundamentals==
When dissolved in water, formic acid converts to formate:
:{{chem2|HCO2H  -> HCO2-  +  H+}}
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==
:[[Image:Testosterone estradiol conversion.png|400px|center]]
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 acid]]s. Formate (or formic acid) is invoked as a leaving group in the [[demethylation]] of some [[sterol]]s.<ref>{{cite journal |doi=10.1016/j.molmet.2019.05.012|title=Formate Metabolism in Health and Disease |year=2020 |last1=Pietzke |first1=Matthias |last2=Meiser |first2=Johannes |last3=Vazquez |first3=Alexei |journal=Molecular Metabolism |volume=33 |pages=23–37 |pmid=31402327 |pmc=7056922 }}</ref> 
These conversions are catalyzed by [[aromatase]] [[enzyme]]s using O<sub>2</sub> as the oxidant. Specific conversions include [[testosterone]] to [[estradiol]] and [[androstenedione]] to [[estrone]].<ref>{{cite journal|author=Lephart, E. D.|title=A Review of Brain Aromatase Cytochrome P450|journal=Brain Res. Rev.|year=1996|volume=22|issue=1|pages=1–26|doi=10.1016/0165-0173(96)00002-1|pmid=8871783|s2cid=11987113}}</ref>  

Formate is reversibly oxidized by the enzyme [[formate dehydrogenase]] from ''[[Desulfovibrio]] gigas'':<ref>{{cite journal | doi = 10.1073/pnas.0801290105| title = Reversible interconversion of carbon dioxide and formate by an electroactive enzyme| date = 2008| last1 = Reda| first1 = Torsten| last2 = Plugge| first2 = Caroline M.| last3 = Abram| first3 = Nerilie J.| last4 = Hirst| first4 = Judy| journal = Proceedings of the National Academy of Sciences| volume = 105| issue = 31| pages = 10654–10658| doi-access = free| pmid = 18667702| pmc = 2491486}}</ref>
:{{Chem2|HCO2- ->  CO2 +  H+  +  2 e-}}

==Formate esters==
Formate esters have the formula HCOOR (alternative way of writing formula ROC(O)H or RO<sub>2</sub>CH).  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]]:<ref name=Ullmann_2009/>
:{{chem2|CH3OH  +  CO -> HCOOCH3}}
Hydrolysis of methyl formate gives formic acid and regenerates methanol:
:{{chem2|HCOOCH3  ->   HCOOH  +  CH3OH}}
In laboratory, formate esters can be used to produce pure carbon monoxide.<ref>{{cite journal
 | last1 = Imberdis
 | first1 = Arnaud
 | last2 = Lefèvre
 | first2 = Guillaume
 | last3 = Cantat
 | first3 = Thibault
 | title = Transition-Metal-Free Acceptorless Decarbonylation of Formic Acid Enabled by a Liquid Chemical-Looping Strategy
 | journal = Angewandte Chemie International Edition
 | volume = 58
 | issue = 48
 | year = 2019
 | pages = 17215–17219
 | doi = 10.1002/anie.201909039
}}</ref> 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.<ref>{{citation | doi = 10.1002/14356007.t11_t01 | chapter = Flavors and Fragrances, 2. Aliphatic Compounds | title = Ullmann's Encyclopedia of Industrial Chemistry | date = 2015 | last1 = Panten | first1 = Johannes | last2 = Surburg | first2 = Horst | pages = 1–55 | isbn = 978-3-527-30673-2 }}</ref>  Ethyl formate is found in some confectionaries.<ref name=Ullmann_2009/>

==Formate salts==
Formate salts have the formula M(O<sub>2</sub>CH)(H<sub>2</sub>O)<sub>''x''</sub>.  Such salts are prone to decarboxylation.  For example, hydrated [[nickel formate]] decarboxylates at about 200 °C with reduction of the Ni<sup>2+</sup> to finely powdered nickel metal:

:{{chem2|Ni(HCO2)2(H2O)2  ->   Ni  +  2 CO2  +  2 H2O  +  H2}}

Such fine powders are useful as [[hydrogenation]] catalysts.<ref name=Ullmann_2009/>

==Examples==
[[File:Copper(II) formate hydrate.jpg|thumb|Copper(II) formate hydrate]]
* [[ethyl formate]], CH<sub>3</sub>CH<sub>2</sub>(HCOO)
* [[sodium formate]], Na(HCOO)
* [[potassium formate]], K(HCOO)
* [[caesium formate]], Cs(HCOO); see [[Caesium#Petroleum exploration|Caesium: Petroleum exploration]]
* [[methyl formate]], CH<sub>3</sub>(HCOO)
* [[methyl chloroformate]], CH<sub>3</sub>OCOCl
* [[triethyl orthoformate]]
* [[trimethyl orthoformate]], C<sub>4</sub>H<sub>10</sub>O<sub>3</sub>
* [[phenyl formate]] HCOOC<sub>6</sub>H<sub>5</sub>
* [[amyl formate]]

==References==

{{Reflist}}

[[Category:Carboxylate anions]]
[[Category:Formates| ]]

[[de:Formiate]]