Tripling of the Unit Cell Volume of the Non-centrosymmetric AlPO₄-<b>SOD</b> after Dehydration: A Structural Study of a Reversible Process

Abstract

The structure of AlPO4-SOD, a microporous aluminophosphate synthesized in a quasi-nonaqueous system using dimethylformamide as template and solvent, was previously reported. Then, various solid state nuclear magnetic resonance techniques applied on the dehydrated compound at 200 degrees C were performed and suggested a rearrangement of one-third of the template molecules inside the sodalite cages and a tripling of the unit cell parameter c. We present here the structure determined from molecular modeling and Rietveld analysis on synchrotron data of AlPO4-SOD dehydrated under vacuum at 100 degrees C together with some solid state NMR experiments of the rehydrated product.