Layered aluminophosphates I. Crystal structure of two novel layered aluminophosphates solved ab initio from powder diffraction data

• Published in: Microporous and mesoporous materials 1999-11, Vol.32 (1), p.17-28
• Main Authors: Kongshaug, Kjell Ove, Fjellvåg, Helmer, Lillerud, Karl Petter
• Format: Article
• Language: English
• Subjects: Ab initio structure solution; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Five-coordinated aluminium; General and physical chemistry; Hydrothermal synthesis; Layered aluminophosphate; Porous materials; Powder diffraction
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/S1387-1811(99)00084-0

The first two examples of layered aluminophosphates with molar ratio P:Al=1 have been synthesized hydrothermally, and their structures have been solved from X-ray powder diffraction data. UiO-13 with composition [NH 3(CH 2) 2NH 3] 2+[Al 2P 2O 9] 2− crystallizes in the orthorhombic space group Pbca with a=9.331 38(11) Å, b=9.660 45(11) Å and c=21.828 69(31) Å. UiO-14 with composition [NH 3(CH 2) 3NH 3] 2+[Al 2P 2O 9] 2− crystallizes in the monoclinic space group P2 1/ c with a=11.650 64(15) Å, b=9.279 36(11) Å, c=9.696 43(11) Å and β=103.1378(9)°. In both compounds the atomic arrangement of the anionic aluminophosphate layers is identical to a building unit of the open framework aluminophosphate AlPO 4-12. The two compounds differ in the stacking sequence of these layers. UiO-13 has an AB stacking sequence, whereas in UiO-14 an AA stacking sequence is present. The compounds contain solely five-coordinated aluminium. Both compounds transform into an amorphous material above 300°C.