[H3N(CH2)4NH3]2[Al4(C2O4)(H2PO4)2(PO4)4]·4[H2O]: A new layered aluminum phosphate-oxalate

A new layered inorganic–organic hybrid aluminum phosphate-oxalate [H3N(CH2)4NH3]2[Al4(C2O4)(H2PO4)2(PO4)4]·4[H2O](AlPO-CJ25) has been synthesized hydrothermally, by using 1,4-diaminobutane (DAB) as structure-directing agent. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by IR, 31P MAS NMR, TG-DTA as well as compositional analyses. Crystal data: the triclinic space group P-1, a=8.0484(7) Å, b=8.8608(8) Å, c=13.2224(11) Å, α=80.830(6)°, β=74.965(5)°, γ=78.782(6)°, Z=2, R1[I>2σ(I)]=0.0511 and wR2(all data)=0.1423. The alternation of AlO4 tetrahedra and PO4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO6 octahedra to form the layered structure with 4,6-net sheet. Interestingly, oxalate ions are bis-bidentately bonded by participating in the coordination of AlO6, and bridging the adjacent AlO6 octahedra. The layers are held with each other through strong H-bondings between the terminal oxygens. The organic ammonium cations and water molecules are located in the large cavities between the interlayer regions.

Graphical abstractThe alternation of AlO4 tetrahedra and PO4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO6 octahedra to form the layered structure with 4,6-net sheet. Oxalate ions are bis-bidentately boned by participating in the coordination of AlO6, and bridging the adjacent AlO6 octahedra.Figure optionsDownload full-size imageDownload as PowerPoint slide