Gravar-mail: The mixed-valent copper thiol­ate complex hexa­kis­{μ(3)-2-[(1,3-dimethyl­imidazol­idene)amino]­benzene­thiol­ato}dicopper(II)tetra­copper(I) bis­(hexa­fluoridophosphate) acetonitrile disolvate dichloro­methane disolvate