ROOM-TEMPERATURE SYNTHESIS OF CRYSTALLINE SOLIDS IN THE SYSTEM ZNO-P2O5-R-H2O, WITH R BEING AN ALKYLAMINE OR AN ALKYLAMMONIUM ION

Five novel materials were synthesized at room temperature in the syste m ZnO-P2O5-R-H2O, where R is an alkylamine or an alkylammonium ion. Th ree were prepared in presence of 1,4-diazabicyclo[2,2,2]octane (DABCO) , two others were synthesized from reaction mixtures containing tetram ethylammonium ions (Me4N+) or hexamethylenetetramine (HMT). The synthe sis occurred at room temperature, the starting pH values ranging from 1 to 4. These five solids were characterized by elemental analysis, SE M, XRD, thermal analysis, and solid-state n.m.r. spectroscopy. Contact with water at room temperature for several days leads to a complete t ransformation of each phase into hopeite. The thermal stability is poo r, too; on calcination under air, amorphization or phase transitions o ccur between 150 and 350-degrees-C. According to the observed properti es, these new materials probably display an interrupted framework with PO3OH or PO2(OH)2 groups.