Unusually high porosity in polymeric cluster cyanides: the synthesis and crystal structure of (H3O)2Zn3[Re6Se8(CN)6]2·20H2O

Mixing of aqueous solutions of the cluster anion [Re6Se8(CN)6]4− and Zn2+ in the presence of acetic acid (pH 3) leads to precipitation of (H3O)2Zn3[Re6Se8(CN)6]2·20H2O having a three dimensional framework of {Zn3[Re6Se8(CN)6]2}2− formed by Re–CN–Zn covalent interactions. This framework occupies only 41.9% of the unit cell volume. The rest of the space is filled by disordered water molecules and hydroxonium cations.