Synthesis and ab Initio Structure Determination from X-Ray Powder Diffraction of MIL-12, a New Layered Fluoroaluminophosphate Templated with 1,3 Diaminopropane: [N2C3H12]Al2(PO4)(OHx, F5−x) (x≈2)

✍ Scribed by N. Simon; N. Guillou; T. Loiseau; F. Taulelle; G. Férey

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 357 KB
• Volume: 147
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8182

✦ Synopsis

MIL-12, formulated Al 2 (PO 4 )(OH x, F 5؊x )N 2 C 3 H 12 , with x+2, is a new layered 6uoroaluminophosphate formed at the early stages of ULM-4 by hydrothermal synthesis using 1-3, Diaminopropane as a template (Al(OH) 3 /H 3 PO 4 /HF/1-3 DAP/H 2 O : ratio 1 : 1 : 3 : 0.5 : 80, 1803C/2 days). It crystallises in the monoclinic space group P2 1 /m with a‫)1(270.11؍‬ A s , b‫210.7؍‬ (2) A s , c‫6901.6؍‬ (8) A s , ‫89.001؍‬ (1)3 and Z‫.2؍‬ Its structure was solved ab initio from conventional X-ray powder di4raction data and re5ned by the Rietveld method with satisfactory crystal-structure model indicators (R B ‫880.0؍‬ and R F ‫؍‬ 0.062) and pro5le factors (R wp ‫421.0؍‬ and R p ‫.)161.0؍‬ It consists of [Al 2 (PO 4 )(OH, F) ؊2 5 ] macroanionic sheets perpendicular to the a axis in which OH ؊ and F ؊ ions are statistically distributed. Aluminum octahedra are linked together to form zig-zag chains running parallel to the b axis; the phosphate groups ensure the connection of the aluminum chains within the (100) layer. Protonated 1-3, Diaminopropane is interleaved between the sheets and ensures the cohesion of the structure by hydrogen bonds. Structural relations with other solids built with the same type of chains are presented.