Polymorphism in intercluster salt system: two crystal structures of [Al13O4(OH)24(H2O)12][H2W12O40](OH) · nH2O

In this paper, we report the syntheses and crystal structures of two intercluster salt compounds, [Al13O4(OH)24(H2O)12][H2W12O40](OH) · 20H2O (1) and [Al13O4(OH)24(H2O)12][H2W12O40](OH) · 24H2O (2). The crystal structures of these compounds show that they are polymorphs to each other with different modes of packing of the View the MathML sourceAl13O4(OH)24(H2O)12+7 and View the MathML sourceH2W12O406- ions. The structures of 1 and 2 can be described as alternating arrangements of ionic clusters that optimize electrostatic interactions and hydrogen bonds between them. The structure of 1 is analogous to the PtS structure and that of 2 is similar to the β-BeO structure with the clusters forming tetrahedral or square planar coordination geometries to each other.