Copper(I) Bromide

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Copper(I) bromide is an inorganic salt with the formula CuBr. When first made, copper(I) bromide is a white crystalline solid, but if it is exposed to sunlight the colour will change from white to green. Bringing a flame to copper(I) bromide will make violet blue colours, which makes it useful in some pyrotechnics.

Synthesis
Copper(I) bromide is created by reduction of [[Copper(II) Bromide|copper(II) bromide with a sulfite ion. This process also creates hydrobromic acid.

Reactions
Copper(I) bromide when reacted with Lewis bases creates molecular adducts. An example of this time of reaction is dimethyl sulfide and copper(I) bromide.

In the complex above, the crystal structure is linear with copper center forming two coordination bonds. A variety of differnt complexes exist that can made is this way. These complexes have uses in organic chemistry both as catalysts in cross-dehydration couplings and atom transfer radical polymerization.

In addition, copper(I) bromide is used in the Sandmeyer reaction to change diazonium salt into aryl bromides.

Structure
Copper(I) bromide is insoluble in many solvents due to the fact that it forms a polymer in solid form. Copper centers in this form have four coordination bonds in a tetrahedral pattern, and each copper is connected to other copper centers by bromide bridges. This structure causes copper(I) bromide to be diamagnetic.