Methanetetracarboxylate

Methanetetracarboxylate

Dots that are highlighted in blue carry a partial negative charge. Red dots are oxygen atoms, black dots are carbon atoms.
Names
Preferred IUPAC name Methanetetracarboxylate
Identifiers
CAS Number	acid: 193197-67-0
3D model (JSmol)	: Interactive image Interactive image acid: Interactive image
PubChem CID	57459306  acid: 19035093
InChI : InChI=1S/C5H4O8/c6-1(7)5(2(8)9,3(10)11)4(12)13/h(H,6,7)(H,8,9)(H,10,11)(H,12,13)/p-4 Key: NKVMCSDLYHGDMD-UHFFFAOYSA-J acid: InChI=1S/C5H4O8/c6-1(7)5(2(8)9,3(10)11)4(12)13/h(H,6,7)(H,8,9)(H,10,11)(H,12,13) Key: NKVMCSDLYHGDMD-UHFFFAOYSA-N
SMILES : C(=O)(C(C(=O)[O-])(C(=O)[O-])C(=O)[O-])[O-] O=C([O-])C(C([O-])=O)(C([O-])=O)C([O-])=O acid: C(=O)(C(C(=O)O)(C(=O)O)C(=O)O)O
Properties
Chemical formula	C(CO−2)4
Molar mass	188.047 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

In chemistry, methanetetracarboxylate is a tetravalent anion with formula C₅O4−8 or C(−CO−2)₄. It has four carboxylate groups attached to a central carbon atom; so it has the same carbon backbone as neopentane. It is an oxocarbon anion, that is, consists only of carbon and oxygen.

The term is also used for any salt with that anion; or for any ester with the C(−C(=O)−O−)₄ moiety.

The salts and esters are relatively uncommon, and their uses appear to be limited to chemical research. Sodium methanetetracarboxylate Na₄C(CO₂)₄ can be obtained by oxidation of pentaerythritol C(CH₂OH)₄ with oxygen in sodium hydroxide solution at pH 10 and about 60 °C, in the presence of palladium as a catalyst.

The anion can be seen as the result of removing four protons from methanetetracarboxylic acid, a hypothetical organic compound with formula H₄C₅O₈ or C(COOH)₄. This acid has not been synthesised (as of 2009), and is believed to be unstable, but its ethyl ester, tetraethyl methanetetracarboxylate, C(COOCH₂CH₃)₄, is a specialty chemical and has been used in organic synthesis.