Dicarbonate

The general structure of dicarbonates

Crystal structure of bis(trifluoromethyl) dicarbonate^[1]

In organic chemistry, a dicarbonate, also known as a pyrocarbonate, is a compound containing the divalent [−O−(C=O)−O−(C=O)−O−] or −C
2O
5− functional group, which consists of two carbonate groups sharing an oxygen atom. These compounds can be viewed as double esters of a hypothetical dicarbonic acid, H
2C
2O
5 or HO−(C=O)−O−(C=O)−OH. Two important examples are dimethyl dicarbonate H₃C−C₂O₅−CH₃ and di-tert-butyl dicarbonate (H₃C−)₃C−C₂O₅−C(−CH₃)₃.

It is one of the oxocarbon anions, consisting solely of oxygen and carbon. Dicarbonate salts are apparently unstable but may have a fleeting existence in carbonate solutions.^[2]>

The term "dicarbonate" is sometimes used erroneously to refer to bicarbonate, the common name of the hydrogencarbonate anion HCO₃⁻ or organic group the ROCO₂H.

See also

• Oxalate
• Peroxodicarbonate
• Pyrophosphate
• Pyrosulfate
• Tricarbonate

References

1. Plácido García, Helge Willner Maximiliano Burgos Paci, Gustavo A. Argüello, Thorsten Berends (2005). "Bis(trifluoromethyl)dicarbonate, CF₃OC(O)OC(O)OCF₃". J. Fluorine Chem. 126: 984–990. doi:10.1016/j.jfluchem.2005.05.002.
2. Zeller, Klaus-Peter; Schuler, Paul; Haiss, Peter (2005). "The hidden equilibrium in aqueous sodium carbonate solutions: Evidence for the formation of the dicarbonate anion". Eur. J. Inorg. Chem. 2005 (1): 168–172. doi:10.1002/ejic.200400445.