Caesium oxalate

Caesium oxalate (standard IUPAC spelling), or dicesium oxalate, or cesium oxalate (American spelling) is a chemical compound with the chemical formula Cs2C2O4. It is a caesium salt of oxalic acid. It consists of caesium cations Cs+ and oxalate anions C2O4(2−).

Preparation
Caesium oxalate can be prepared by passing carbon monoxide and carbon dioxide over caesium carbonate at 380 °C:


 * Cs2CO3 + CO → Cs2C2O4

Other alkali carbonates do not undergo transformation to oxalate.

Caesium carbonate can react with oxalic acid in aqueous solution to give caesium oxalate.


 * Cs2CO3 + H2C2O4*2H2O → Cs2C2O4*H2O + CO2 + 2 H2O

Chemical Reactions
Caesium oxalate can be reduced back into caesium carbonate and carbon monoxide by thermal decomposition.


 * Cs2C2O4 → Cs2CO3 + CO

Double salts
Compounds that contain caesium and another element in addition to the oxalate anion are double salts of caesium and oxalate. The oxalate may form a complex with a metal that can make a salt with caesium.

Examples include: Mixed anion compounds containing caesium, oxalate and another anion also exist, such as the uranyl sulfate above, and caesium bis(oxalato)borate (CsBOB) (Cs[B(C2O4)2]).