title: Structural characterisation of phosphate materials: new insights into the spatial proximities between phosphorus and quadrupolar nuclei using the D-HMQC MAS NMR technique.
abstract: We show in this article how the spatial proximity between phosphorus and quadrupolar nuclei can be efficiently and easily investigated with the D-HMQC (Dipolar Hetero-nuclear Multiple-Quantum Coherences) NMR technique. Compared to the commonly used CP-HETCOR (Cross-Polarisation HETero-nuclear CORrelation) sequence, the D-HMQC pulse scheme exhibits a higher sensitivity and a better robustness with respect to spinning frequency, electronic shielding and quadrupole interaction, and thus does not require time-consuming and complicated optimisation procedures. The advantages of the D-HMQC are demonstrated in this article through the acquisition of (31)P/S through-space two-dimensional correlation NMR spectra providing unreported structural information on (i) a sodium alumino-silicate glass doped with only 3% of P(2)O(5), (ii) a potassium boro-phosphate glass containing BO(3) and BO(4) groups and (iii) a crystalline zirconium vanado-phosphate. All these systems, representative of the most important mixed phosphate network materials, cannot be correctly investigated with the conventional CP-HETCOR NMR technique.
authors.affiliation: Université Lille Nord de France, CNRS UMR 8181, Unité de Catalyse et de Chimie du Solide, Université Lille 1, Ecole Nationale Supérieure de Chimie de Lille, Villeneuve d'Ascq, France. gregory.tricot@ensc-lille.fr
authors.forename: G
authors.initials: G
authors.lastname: Tricot
authors.forename: O
authors.initials: O
authors.lastname: Lafon
authors.forename: J
authors.initials: J
authors.lastname: Trébosc
authors.forename: L
authors.initials: L
authors.lastname: Delevoye
authors.forename: F
authors.initials: F
authors.lastname: Méar
authors.forename: L
authors.initials: L
authors.lastname: Montagne
authors.forename: J-P
authors.initials: JP
authors.lastname: Amoureux