Three-Dimensional Open-Framework Germanate Built from a Novel Ge₁₃ Cluster and Containing Two Types of Chiral Layers

A new open-framework germanate [Ge₁₅O₃₀(OH)₄]·2­(H₂tren), denoted SU-69, was synthesized under hydrothermal conditions with tris­(2-aminoethyl)-amine (tren) as a structure directing agent (SDA). SU-69 crystallizes in a monoclinic space group (<i>C</i>2/<i>c</i>, No. 15) with <i>a</i> = 20.2656(7) Å, <i>b</i> = 11.6250(4) Å, <i>c</i> = 18.5602(10) Å, and β = 90.528(4)°. The framework of SU-69 is built from a novel Ge₁₃O₂₇(OH)₂ (Ge₁₃) cluster with two additional GeO₃(OH) tetrahedra. Two types of chiral 3,6-net building layers are found in the framework, which alternately stack and connect to form a three-dimensional achiral framework with a two-dimensional 10 × 12-ring channel system. The SDA molecules interact with the framework via H-bonds. The thermal stability of as-synthesized SU-69 has also been investigated