Synthesis and characterization of perchlorate enclathrated aluminogermanate sodalite and its potassium and silver derivatives

Abstract

Perchlorate enclathrated sodalite with aluminogermanate host framework has been obtained from low temperature hydrothermal synthesis at 373K. In addition mixed sodium, potassium and silver perchlorate sodalite is obtained by aqueous cation exchange method. The crystal structure of Na8[AlGeO4]6(ClO4)2, Na3.2K4.8[AlGeO4]6(ClO4)2 and Na3.9Ag4.1[AlGeO4]6(ClO4)2 sodalites were refined from X-ray powder data in the space group P 4 3n: a = 9.249 A, V = 791.35 A, Rwp = 0.2230, Rp = 0.1609 and Al-O-Ge angle is 140.930 and a = 9.257 A, V = 793.28 A, Rwp = 0.1596, Rp = 0.1180 and Al-O-Ge angle is 141.080, a = 9.195 A, V = 775.95 A, Rwp = 0.2211, Rp = 0.1662 and Al-O-Ge angle is 139.034 respectively. The Al MAS NMR study confirms alternating Ge and Al ordering of sodalite framework, while Na give insights into the structure and dynamics of the cage fillings. The recorded Infrared and Raman spectra show absorption band typical for the sodalite structure. Thermogravimetric analysis has provided information on the extent of perchlorate entrapment, stability within the sodalite cage and decomposition properties. SEM study shows the retention of cubical morphology of the sodalite derivatives.