Copper(II) cyanurate

Copper(II) cyanurate (C₃HCuN₃O₃) is an organic compound. It has very few uses, and is more often encountered accidentally, rather than actually synthesised.

Copper(II) Cyanurate

Names
IUPAC name Copper 6-hydroxy-1,3,5-triazine-2,4-bis(olate)
Other names Copper 1,3,5-triazine-2,4,6-triol
Identifiers
3D model (JSmol)	Interactive image
PubChem CID	137177301
InChI InChI=1S/C3H3N3O3.Cu/c7-1-4-2(8)6-3(9)5-1;/h(H3,4,5,6,7,8,9);/q;+2/p-2 Key: IXMUUTDLXYTMPF-UHFFFAOYSA-L
SMILES [Cu+2].[O-]c1nc(O)nc([O-])n1
Properties
Chemical formula	C3HCuN3O3
Molar mass	190.60434
Appearance	purple powder
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

It is often found when the copper concentration in an outdoor swimming pool is too high. It also occurs with heat pumps due to acid in the insulation, and it reacts with cyanuric acid (which is added as a chlorine stabilizer) to produce copper cyanurate. This phenomenon is called 'Purple Cyanurate', as it discolours the surfaces and the water of the pool to a purple shade.

Synthesis

Copper cyanurate can be created by reacting cyanuric acid with copper oxide.

CuO + C₃H₃N₃O₃ → C₃HCuN₃O₃ + H₂O.

Joanneumite is a rare natural mineral found in bat guano with formula Cu(C₃N₃O₃H₂)₂(NH₃)₂ which is an ammine.

By heating copper compounds, such as the nitrate or carbonate with molten urea up to 190°C, they are largely converted to the lavender coloured joanneumite compound. This is dissolved and then recrystallised from a hot strong ammonia solution. If instead a weak (2%) cold ammonia solution is used, the dark purple compound CuC₃N₃O₃H•2NH₃ is formed instead.

A green coloured copper cyanurate containing no extra water or ammonia ligands also exists: Cu₃(C₃N₃O₃)₂.

Applications

Copper cyanurate has no known practical uses. The only place it commonly occurs is as an adverse effect of high levels of copper in swimming pools, and is more commonly seen as a nuisance.