(NPr4)2[Cu(MeCN)]2[Cu8(i-mnt)6].(MeCN)0.5.(THF)0.25 is prepared by electrocrystallization of a solution of (NPr(4))(4)[Cu(I)(8)(i-mnt)(6)]; the crystal structure consists in bidimensional layers characterised by coordination of copper atoms by the cyano groups of the iso-maleonitriledithiolate ligand of the octa-copper cluster.