Isotropic chemical shifts and quadrupolar parameters for oxygen-17 using dynamic angle spinning NMR

The Route to the Structure Determination of Amorphous Solids: A Case Study of the Ceramic Si3B3N7

“…This problem can be overcome by employing techniques capable of averaging the fourth Legendre polynomial. Among the various strategies developed-dynamic angle spinning (DAS), [49,50] double rotation (DOR), [51,52] and multiple quantum MAS (MQMAS) [53][54][55][56][57] -the latter has attracted much attention because of the versatility and ease of use of the approach.…”

17O NMR Studies of Low Silicate Zeolites

“…New NMR techniques, e.g., dynamic angle spinning (DAS) [3,4], double rotation (DOR) [5], and multiple-quantum excitation in combination with fast spinning (MQMAS) [6], were recently developed for quadrupole nuclei with half-integer spins, and, in addition, the perturbing effect of the electric quadrupole interaction is reduced at the higher magnetic fields, which are now available. Numerous 17 O NMR investigations applying these techniques were performed, in order to correlate the obtained NMR parameters of resolved oxygen signals with structure data obtained by diffraction methods: Grandinetti et al [7] investigated the SiO 2 polymorph coesite, Mueller et al [8] measured the 17 O signals of diopside, forsterite, clinoenstatite, wollastonite, and larnite by DAS NMR, and Bull et al [9,10] investigated the silicon-rich zeolites Sil-Y and ferrierite by 17 O DOR NMR. We investigated several hydrated zeolites by 17 O 3Q MAS and DOR NMR and demonstrated the reasonably good resolution in the field of 17.6 T, whereas we obtained nonsufficient resolution in the lower field of 11.7 T [11,12].…”

27Al Multiple-Quantum MAS NMR of Mechanically Treated Bayerite (α-Al(OH)3) and Silica Mixtures

“…The relatively high gyromagnetic ratio and 100% natural abundance of 27 Al (spin quantum number I = 5 2 ) make it an attractive nucleus for NMR. However, the ability of solid-state 27 Al NMR spectra to yield structural information is often hindered by the presence of significant second-order quadrupolar broadening.…”

“…The relatively high gyromagnetic ratio and 100% natural abundance of 27 Al (spin quantum number I = 5 2 ) make it an attractive nucleus for NMR. However, the ability of solid-state 27 Al NMR spectra to yield structural information is often hindered by the presence of significant second-order quadrupolar broadening. Conventional line-narrowing methods, such as magic angle spinning (MAS), may improve resolution but are unable to average this broadening mechanism fully [3].…”

“…In this work, 27 Al NMR is used to study some aluminosilicate precursors of mullite (Al 6 Si 2 O 13 ), an important technical ceramic that displays excellent hightemperature strength, low thermal expansion, and good chemical stability [7]. The conventional method for producing ceramics from minerals and oxides is by solid-state reaction, involving heating to high temperatures to induce the necessary diffusion processes.…”