Solid-state 31P NMR

Fig. 4. 31p solid-state NMR spectra of pure VPI-5 and pure AIPO4-8. 

Figure 17 Structural model of rat dentin based on the 31P solid-state NMR measurements. (Reprinted with permission from Ref. 33. 2009 American Chemical Society.)...

P solid-state NMR spectra were used to characterise Si02-tethered rhodium complexes derived from RhCl(PPh3)3 or RhH(CO)(PPh3)3.210... 

The issue of chirality continues to be an important issue in drug development. With the advent of solid-state NMR, enantiomeric purity of a sample may be measured directly. A number of reports in the literature demonstrate the ability of 13C or 31P solid-state NMR to differentiate between optically pure material and... 

Lindner et al. carried out detailed studies on the use of the sol-gel procedure to obtain new materials as suitable matrices [45]. A co-condensation of Si(OR)4, Si(OR)3-spacer-Si(OR)3 and Si(OR)3-spacer-ligand resulted in new hybrid materials, the properties of which strongly depended upon the spacer and the ratio of the different components used. Most of these materials were characterised with IR, EXAFS, and EDX spectroscopy, scanning electron microscopy and solid state NMR spectroscopy. Solid state 31P NMR was used to quantify the mobility of the interphases the changes in line-... 

Fig. 9 Examples of simplifying solid state NMR spectra by the TOSS and delayed decoupling pulse sequences. Shown is a comparison of the 31P CP/MAS NMR spectrum of fosinopril sodium utilizing the standard pulse sequence (A) and the TOSS routine (B). Also shown is the full 13C CP/MAS NMR spectrum of fosinopril sodium (C) and the nonprotonated carbon spectrum (D) obtained from the delayed decoupling pulse sequence utilizing a 80 /us delay time. Signals due to the methyl carbon resonances (0-30 ppm) are not completely eliminated due to the rapid methyl group rotation, which reduces the carbon-proton dipolar couplings.

The electrostatically favored cation (Li) and anion (RE) arrangement implies the presence of two different E-, Si- and Li sorts, which has been established by solution and solid-state NMR spectroscopy. The electronic structures of the mixed-valent pnictides 10 and 11 have been simply described as electron-deficient clusters with delocalized framework electrons. Formally the latter consist of two low-valent anediyl moieties RE and eight andiides (RE)2- (E = P, As). The relatively large E-E distances of >4 A exclude the occurrence of localized E-E bonds. However, delocalization of the cluster valence electrons is achieved without Li-Li bonds via Li-mediated multiple bonding. Evidence for this has been seen in the NMR spectra (31P, 7Li, 29Si), which are in accordance with the electron delocalization model (see later discussion). 

P and 19F NMR spectroscopy), and attempts to record a CP/MAS solid-state NMR spectrum (19F, 31P, 23Na) failed because of the large line-broadening by the 23Na ions (I = 3/2) and strong spin-spin coupling. 

The size and orientation of the 31P CSA tensor have been calibrated from single-crystal solid state NMR data of barium diethylphosphate [31]. The projection angles 6CHa22 and i between the 1H,13C-dipolar coupling and the components of the 31P-CSA-tensor de-... 

SiMouO ]4-.134 The structure of the heteropoly blue species (four-electron-reduced PM012O40]3-) formed in the molybdenum blue determination of phosphorus has been reported135 and a review of molybdate heteropoly blues has appeared.130 A stability index of polyanion structures has been discussed.137 The presence of two PMo, anions in aqueous solutions of molybdate and phosphate has been demonstrated by 31P NMR.138 Solid state NMR (nonspinning and MAS techniques) has been used for characterization of heteropolyanions.139 Molybdenum-95 NMR spectra of some polymolybdates have been reported.140... 

Principal 31P Chemical Shift Tensor Components as Determined by Solid State NMR... 

Key Words P-31 solid-state NMR, 31P CP/MAS, Ultra-fast MAS, Phosphorylated amino acids, Nucleotides, Nucleic acids, Phosphate glasses, Aluminophosphates, Molecular sieves, Catalysts, Polyoxometalate (POM), Metal-organic framework (MOF), Inclusion complexes. 

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