Interrupted silicogermanate with 10-ring channels: synthesis and structure determination by combining rotation electron diffraction and powder X-ray diffraction

Abstract

Silicogermanate (JU110) with an interrupted open-framework has been synthesized by using a hydrothermal method using 1,1′-(1,4-phenylenebis(methylene))bis(1-methylpyrrolidin-1-ium) hydroxide as an organic structure-directing agent (OSDA). Silicon and fluoride anions were introduced to the concentrated-gel synthesis system, and different synthetic parameters influencing the synthesis were discussed. The structure of JU110 was characterised by using rotation electron diffraction (RED) and high-resolution powder X-ray diffraction. JU110 crystallizes in the space group Fm2m (No. 42) with a = 13.9117(2) Å, b = 18.2980(3) Å and c = 32.7800(6) Å. The structure is constructed by the sti layers found in the STI framework that are pillared by D4R/Ge₇ units to form a large cavity, showing 10-ring openings along [100] and 9-ring openings along [110]. Thermal stability studies showed that the framework was maintained with the loss of water molecules, but collapsed with the removal of charge-compensating cations.