2D layered coordination polymer based on an unusual mixed valence Cu(III)/Cu(I)bis-1,2-diselenolene compound

The crystal structure of a new mixed-valence Cu(III)/Cu(I) compound containing the ligand pds(2-) (pds, pyrazine-2,3-diselenolate) shows a unique packing pattern with 2D layers formed by the coordination of the Cu(I) countercations to both the pyrazine N and Se atoms of the [Cu-III(pds)(2)](-) complex, with a distorted square pyramidal environment for Cu(I) centres.