RING OF 12 HYDROGEN-BONDED WATER-MOLECULES IN A PYRITE-LIKE FRAMEWORK OF HEPTACYANODICUPRATO(I) CADMATE(II) [CDCU2(CN)7]3-

The single crystal structure of [H31O14][CdCu2(CN)7] demonstrates an interpenetrating three-dimensional array of pyrite-like but negatively-charged framework [Cd2+{Cu2(CN)7}5-] and a ring of 12 water molecules connected successively with two other waters, partly protonated, [Hx(H2O)2Hy(H2O)12]3+ (x + y = 3), the ring of which encircles the pyrosilicate-like heptadicuprate(I) anion about the Cu-(CN)-Cu axis.