Copper(II) borate

Copper(II) borate is an inorganic compound with the formula Cu3(BO3)2. It consists of copper atoms in their cupric oxidation state and orthoborate groups. In the 19th century it was proposed to be used as a green pigment to replace the very toxic paris green. It has been studied for it photocatalytic properties.

Preparation
Copper(II) borate can be prepared by heating a stoichiometric mixture of copper(II) oxide and diboron trioxide to 900 °C.


 * 3CuO + B2O3 -> Cu3(BO3)2