Copper(II) oxalate are

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

s with the chemical formula . The value of x can be 0 and 0.44. One of these species is found as the secondary mineral

moolooite Moolooite is a rare blue-green mineral with the formula Cu(C2O4)·n(H2O) (n<1) ( copper(II) oxalate hydrate). It was discovered in Bunbury Well, ...

(0.44 hydrate). The anhydrous compound has been characterized by

X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

. Many

transition metal oxalate complex Transition metal oxalate complexes are coordination complexes with oxalate (C2O42−) ligands. Some are useful commercially, but the topic has attracted regular scholarly scrutiny. Oxalate (C2O42-) is a kind of dicarboxylate ligand. As a small, sym ...

es are known. Copper(II) monooxalates are practically insoluble in all solvents. They are

coordination polymer Coordination may refer to: * Coordination (linguistics), a compound grammatical construction * Coordination complex, consisting of a central atom or ion and a surrounding array of bound molecules or ions ** A chemical reaction to form a coordinat ...

Synthesis

Copper(II) oxalate can be produced by precipitation from acidified aqueous copper(II) salts and

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and chemical formula , also written as or or . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name i ...

. ::

Reactions

Upon heating to 130 °C, the hydrated copper(II) oxalates convert to the anhydrous cupric oxalate. Further heating at higher temperatures under an atmosphere of hydrogen gives copper metal, suitable as a reagent. The hydrates bind

Lewis base A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

s. Hydrated copper(II) oxalate reacts with alkali metal oxalates and

ammonium oxalate Ammonium oxalate is a chemical compound with the chemical formula . Its formula is often written as or . It is an ammonium salt of oxalic acid. It consists of ammonium cations () and oxalate anions (). The structure of ammonium oxalate is . A ...

to give bis(oxalato)cuprate: :

Uses

Copper oxalate is used as a catalyst for organic reactions, as a stabilizer for acetylated

polyformaldehyde Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. Short-chained POM (chain length ...

Related compounds

*Cuprous oxalates.

References

{{Oxalates Copper(II) compounds Oxalates Inorganic compounds