STRUCTURE OF AN UNUSUAL ALUMINUM PHOSPHATE ([AL5P6O24H]2- 2[N(C2H5)3H]+.2H2O) JDF-20 WITH LARGE ELLIPTIC APERTURES

The structure and thermal properties of a new large-pore three-dimensional aluminophosphate are reported. The P/Al ratio of this compound is 6:5, the structure consists of Al-centered and P-centered tetrahedra in which all the Al vertices are shared, but not all the P vertices, giving rise to an interrupted structure type. The framework contains 20-membered rings with elliptical apertures having a free diameter of 6.2 by 14.5 Å intersected by smaller 10- and 8-membered rings. In these channels are water molecules and triethylammonium cations which are hydrogen bonded to the framework. The space group of the compound is C2/c, with a = 32.035(12), b = 14.308(3), c = 8.852(2) Å, β = 104.65(2)°, and V = 3925.6 Å3. The crystal structure has been refined to yield residuals of R = 0.126 and Rw = 0.113. © 1993 Academic Press, Inc.