Hydrothermal synthesis and characterization of two ammonium-templated cobalt aluminophosphates

Two new cobalt-substituted aluminophosphates (CoAPOs) with ammonium cation- templates, (NH4)(2)[(OH)(0.95)(H2O)(0.05)](2)[Co0.05Al0.95](2)(PO4)(2) and (NH4)[(OH)(0.95)(H2O)(0.05)][Co0.025Al0.975](2). 2H(2)O, have been hydrothe rmally synthesized and characterized by single-crystal X-ray diffraction, t hermogravimetry, elemental analysis, mass spectrometry and IR spectroscopy. The first compound crystallizes in a new zeolite-like structure type where Co2+ substitutes for Al3+ at both trigonal bipyramidal and octahedral site s. The second CoAPO is isostructural with a known aluminophosphate, AlPO-15 , where all metal sites are octahedrally coordinated. The channels in both compounds are occupied by the charge-balancing NH4+-templates. The compound s are stable up to ca. 350 degrees C above which temperature they become am orphous.