Synthesis, structure and phase transition of a new microporous aluminophosphate [C₄N₂H₁₄]²⁺ [H₂Al₃ P₃O₁₄]^2-

In the presence of N-methyl-1, 3-diaminopropane, a new microporous aluminophosphate compound [C₄N₂H₁₄]²⁺ [H₂Al₃P₃ O₁₄]^2-(1) was synthesized under hydrothermal condition. Single-crystal X-ray diffraction structural analysis showed that compound 1 crystallizes in the orthorhombic space group Pbca with a=1.59839(11) nm, b=0.99402(6) nm, c=1.82261(11) nm, V=2.8958(3) nm³. Its framework consists of AlO₅/AlO₆ and PO₄ units forming 10-ring channels along [010] direction, where the templates exists. Compound 1 transformed to AlPO₄-25(ATV) upon calcination at 550 °C. It was further characterized by powder X-ray diffraction(PXRD), inductively coupled plasma(ICP) analysis, scanning electron microscopy(SEM), thermal gravimetric(TG) analysis, and elemental analysis.