Multifield magic-angle spinning and double-rotation nuclear magnetic resonance studies of a hydrated aluminophosphate molecular sieve: AlPO4-H2

✍ Scribed by Gordon J. Kennedy; John B. Higgins; Cynthia F. Ridenour; Hong-Xin Li; Mark E. Davis

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 487 KB
• Volume: 4
• Category: Article
• ISSN: 0926-2040
• DOI: 10.1016/0926-2040(94)00046-f

✦ Synopsis

AlPO,-H2 is a microporous hydrated aluminophosphate, structurally related to VPIS, whose framework has highly elliptical lo-ring channels (2.9 x 7.6 A) parallel to the c crystallographic axis. To resolve a previously reported discrepancy between nuclear magnetic resonance (NMR) and X-ray diffraction (XRD) data a highly crystalline AlPO,-H2 has been further characterized with *'Al and 31P magic-angle spinning (MAS) NMR at 11.7 T and "Al double-rotation (DOR) NMR at 4.7 T. These present NMR data definitively show that the true space group symmetry of the AlPO,-H2 framework structure is triclinic rather than the higher orthorhombic symmetry proposed earlier from XRD studies.