Synthesis, structure and characterization of a novel germanium dioxide with occluded tetramethylammonium hydroxide

Abstract

A crystalline microporous germanate has been discovered. This novel material is based on a germanium dioxide framework and was synthesised hydrothermally at 180 °C in the presence of NMe₄OH as templating agent. A single-crystal X-ray study of the compound revealed a monoclinic germanium dioxide clathrate with space group P2₁/n and unit cell parameters a= 9.690(4), b= 9.231(5), c= 18.019(8)Å, β= 98.46(4)°, Z= 4, R= 0.0417 and R′= 0.0434. The compound has a framework consisting of GeO₄ tetrahedrons and GeO₅ trigonal bipyramids which form four-, six- and eight-membered ring channels along the c axis. The cation NMe₄⁺ is located in the six-membered ring channel and is a key factor in the formation and stability of the framework.