An anionic framework aluminophosphate |(CH 2) 6N 4H 3·H 2O|[Al 11P 12O 48] and computer simulation of the template positions

Abstract

A new aluminophosphate compound |(CH 2) 6N 4H 3·H 2O|[Al 11P 12O 48] (denoted AlPO-CJB2) with a three-dimensional open framework and an Al/P ratio of 11/12 has been synthesized solvothermally by using hexamethylenetetramine as a template. It was characterized by X-ray powder diffraction, inductively coupled plasma, elemental (CHN), and thermogravimetric analyses, and the structure was determined by single-crystal X-ray diffraction analysis. AlPO-CJB2 crystallizes in the trigonal space group R-3c with a=14.088(2) Å, c=42.199(9) Å, and Z=6. Its structure features two new kinds of cages, i.e., cage 1, 4 124 36 68 6 and cage 2, 4 126 12. The two cages alternate along the [0 0 1] direction forming an infinite column by sharing a common snowflake-like chiral motif, which is constructed from an AlO 6-centered six four-membered rings. The title compound is constructed from strictly alternating Al polyhedra (AlO 4 and AlO 6) and P tetrahedra (PO 4) via bridging oxygen atoms, and presents a new type of stoichiometry with an Al/P ratio of 11/12 in the aluminophosphate family. Computer simulation was used to determine the possible positions of the organic template within the cages.