Synthesis and characterization of an aluminogermanate SU-46 with a zeolite structure

A new three-dimensional open-framework aluminogermanate (denoted as SU-46) was synthesized solvothermally in a quasi nonaqueous media using diethylenetriamine (DETA) as the structure-directing agent. SU-46 was characterized by in situ X-ray powder diffraction (XRPD), infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) OD scanning and transmission electron microscopes, elemental analysis, and thermogravimetric analysis (TGA). The structure of SU-46 was determined by single-crystal X-ray diffraction. SU-46 is isostructurat to the gallogermanate UCSB-9GaGe, having a new zeolite-framework structure built up by the secondary building unit 4=1. The structure is formed by vertex-sharing AlO4 and GeO4 tetrahedra and contains intersecting 8-ring channels in three different directions. The framework density of SU-46 is very low, 13.8 T atom/ 1000 angstrom(3). SU-46 is built from layers containing 3- and 9-rings. The building layer is compared to similar layers found in several pure germanates, borogermanates, and the gallogermanate UCSB-9GaGe. The structure refinement shows that aluminum and germanium share the sanne tetrahedral (T) positions. Both long-range ordering and short-range ordering of Al and Ge are present in SU-46. SU-46 was thermally, stable up to 300 degrees C. Crystal data: C4N3H15 vertical bar[Al2Ge3O10], hexagonal P (6) over bar 2c (No. 190), a = 7.524(l) angstrom, c = 14.746(3) angstrom, Z = 2, R-1 = 0.0251 (F-2 > 2 sigma(F-2)), and wR(2) = 0.0647 (all data).