title: 3D correlation NMR spectrum between three distinct heteronuclei for the characterization of inorganic samples: Application on sodium alumino-phosphate materials.
abstract: We report here an original NMR sequence allowing the acquisition of 3D correlation NMR spectra between three distinct heteronuclei, among which two are half-integer spin quadrupolar nuclei. Furthermore, as two of them exhibit close Larmor frequency, this experiment was acquired using a standard triple-resonance probe equipped with a commercial frequency splitter. This NMR technique was tested and applied to sodium alumino-phosphate compounds with31P as the spin-1/2 nucleus and23Na and27Al as the close Larmor frequencies isotopes. To the best of our knowledge, such experiment with direct31P and indirect27Al and23Na detection is the first example of 3D NMR experiment in solids involving three distinct heteronuclei. This sequence has first been demonstrated on a mixture of Al(PO3)3and NaAlP2O7crystalline phases, for which a selective observation of NaAlP2O7is possible through the 3D map edition. This 3D correlation experiment is then applied to characterize mixing and phase segregation in a partially devitrified glass that has been proposed as a material for the sequestration of radioactive waste. The31P-{23Na,27Al} 3D experiment conducted on the partially devitrified glass material conclusively demonstrates that the amorphous component of the material does not contain aluminum. The as-synthesized material thus presents a poor resistance against water, which is a severe limitation for its application in the radioactive waste encapsulation domain.
authors.affiliation: Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nagashima
authors.affiliation: Univ. Lille, CNRS, UMR 8516 - LASIR - Laboratoire de Spectrochimie Infrarouge et Raman, F-59000 Lille, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Tricot
authors.affiliation: Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Trébosc
authors.affiliation: Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France; Institut Universitaire de France, 1 rue Descartes, Paris Cedex 5 75231, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Lafon
authors.affiliation: Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Amoureux
authors.affiliation: Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France. Electronic address: frederique.pourpoint@ensc-lille.fr.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Pourpoint
keywords: 3D; Alumino-phosphate; Close Larmor frequencies; HMQC; INEPT