Nonaqueous Synthesis and Characterization of a New 2-Dimensional Layered Aluminophosphate [Al₃P₄O₁₆]^3-· 3[CH₃CH₂NH₃]⁺

The compound [Al₃P₄O₁₆]^3-·3[CH ₃CH₂NH₃]⁺has been synthesized from the nonaqueous system H₃PO₄-(iPrO)₃Al-CH₃CH ₂NH₂-CH₃(CH₂)₃OH. It has been definitively characterized by single-crystal X-ray diffraction, with space groupP2₁/mand unit cella=8.920(2),b=14.896(2),c=9.363(2) Å,β=106.07(2)°, andV=1191.6(4)ų. The structure consists of [Al₃P₄O₁₆]^3-sheets with a 4×6×8 network. This contains individual AlO₄and PO₄centered tetrahedral in the ratio of 3/4, in which all AlO₄vertices are shared but each PO₄has one terminal P=O. These are projected alternatively above and below the 2-D sheet and are hydrogen bonded to the ethylammonium ions which serve to template the structure. They give rise to elliptical eight-membered rings, which have a cavity size of 3.8×6.0Å and anAAAAstacking sequence. This compound thus strengthens the family of 4×6×8 and 4×6×12 nets withAAAAorABABstackings for [Al₃P₄O₁₆]^3-, allowing rationalization based on the amine template length and functional multiplicity. Additional characterizations of the compound by XRD, SEM, IR spectroscopy, inductive coupled plasma analysis, TGA, and DTA are also described.