title: Multifield magic-angle spinning and double-rotation nuclear magnetic resonance studies of a hydrated aluminophosphate molecular sieve: AlPO4-H2.
abstract: AlPO4-H2 is a microporous hydrated aluminophosphate, structurally related to VPI-5, whose framework has highly elliptical 10-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 AlPO4-H2 has been further characterized with 27Al and 31P magic-angle spinning (MAS) NMR at 11.7 T and 27Al double-rotation (DOR) NMR at 4.7 T. These present NMR data definitively show that the true space group symmetry of the AlPO4-H2 framework structure is triclinic rather than the higher orthorhombic symmetry proposed earlier from XRD studies.
authors.affiliation: Mobil Research and Development Corporation, Paulsboro Research Laboratory, NJ 08066, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Kennedy
authors.forename: J B
authors.initials: JB
authors.lastname: Higgins
authors.forename: C F
authors.initials: CF
authors.lastname: Ridenour
authors.forename: H X
authors.initials: HX
authors.lastname: Li
authors.forename: M E
authors.initials: ME
authors.lastname: Davis
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010710:Phosphates / Q000737:chemistry*; D012399:Rotation
chemical_list: D017607:Aluminum Compounds; D010710:Phosphates; C012714:aluminum phosphate