Characterization of local environments in crystalline borophosphates using single and double resonance NMR

New Insights into Frustrated Lewis Pairs: Structural Investigations of Intramolecular Phosphane–Borane Adducts by Using Modern Solid-State NMR Techniques and DFT Calculations

“…That is, both parts of the REDOR curve would actually result in slightly different values of effective dipolar coupling constants. We speculate that these distortions result mainly from heteronuclear interactions with the homonuclearly coupled proton spin reservoir or other systematic errors as already described in the literature. − The origin of these deviations can be explored by conducting these REDOR experiments with 1 H multipulse decoupling or on perdeuterated compounds, to be examined in future work.…”

Description of the Intermediate Length Scale Structural Motifs in Sodium Vanado-phosphate Glasses by Magnetic Resonance Spectroscopies

“…The rotational echo adiabatic passage double resonance (REAPDOR) ,− sequence has been applied in order to quantitatively probe the heteronuclear dipolar interaction between the 31 P and 51 V nuclei and to determine the number of vanadate units connected to the phosphate species. The application of the REAPDOR sequence on inorganic materials has been extensively described in literature. − This sequence allows building curves expressing the evolution of dephasing signal (S 0 – S)/S 0 versus an echo delay. The S 0 signal is obtained after a 90°−τ–180°−τ 31 P spin–echo sequence during which the heteronuclear 31 P/ 27 Al dipolar interaction has been averaged out.…”

“…The (S 0 – S)/S 0 versus τ curves can then be related to the dipolar interaction intensity that depends on the P–V distance and the number of vanadium ions around phosphorus. By assuming a constant P–V distance, the READPOR results presented here can be used to determine the number of vanadium attached to each phosphate species ( m in the Q n m notation) as it has previously been used in the case of alumino-phosphate or boro-phosphate glasses. − More details about the acquisition parameters have been inserted in the figure captions.…”

Ab initio study of stability and quadrupole coupling constants in borophosphates

“…[33][34][35][36][37][38][39] For boron-containing phases and especially glasses, of particular interest are the structural distortions of the MO n , BO 3 , BO 4 and PO 4 polyhedra and their linking, which are intensively studied by NMR and first-principles methods. [40][41][42][43][44][45][46][47][48] While borates are well investigated, only a few ab initio calculations are known for borophosphates. 49,50 Studies of a series of borophosphates consisting of different networks of the distorted polyhedra have not been carried out.…”