Synthesis and Structure of an Aluminum Borate Chloride Consisting of 12-Membered Borate Rings and Aluminate Clusters

A new aluminum borate chloride (PKU-8) was synthesized in a flux of boric acid, and the structure was established using powder X-ray diffraction techniques. PKU-8 contains an unusual framework structure of a large cage consisting of 12-membered borate rings [B₁₂O₃₀] and aluminate octahedra clusters [Al₇O₂₄].