13C CPMAS NMR spectra

Solid state 13C CPMAS NMR spectra of Wheat High Molecular Weight (W.HMW) subunits show well resolved resonances identical with spectra of dry protein and peptide samples [24], Most of the amino acids side-chain resonances are found in the 0-35 ppm region followed by the alpha resonances of the most abundant amino acids glycine, glutamine and proline at chemical shifts of 42, 52 and 60 ppm, respectively, and the carbonyl carbons show a broad peak in 172-177 ppm region. The CPMAS spectra of hydrated whole HMW provides important information on the structural characteristics. 

Figure 31 100.6 MHz 13C CPMAS NMR spectra of [l-13C]Val-labelled D85N mutant at...

Figure 35 13C CPMAS NMR spectra of [l- 3C]Val- and [3- 3C]Ala-labelled bR reconstituted in DMPC bilayer (1 50 mole ratio) at various temperatures from 40 (A) to —10 °C (D). The methylene peak-position of the fatty acyl chain of the lipid at 32 and 30 ppm is a good indicator of the gel and liquid-crystalline phase, respectively. From Ref. 206 with...

Chemical shifts of 13C CPMAS NMR spectra of 4-(4-fluorophenyl)-2- 4-[4-(3-trifluoromethylphenyl)piperazino]butyl -2,3-dihydro-lH-pyrido [l,2-c]pyrimidinel,3-dione and its hydrochloride salt were unambiguously assigned by theoretical calculations at GIAO/DFT (B3LYP/6-311 +G ) level (08JST325). Absolute energies, bond angles, and bond distances of 9,10-dimethoxy-l, 6,7,11 fc-tetrahydro-2H,4H-[l, 3]oxazino[4,3-fl]... 

Polymerization of pyrogallol (measurement of optical density) ring cleavage of pyrogallol and catechol (measurement of C02 release) yields of humic polymers IR and 13C CPMAS NMR spectra resembling natural HAs... 

Birnessite (8-Mn02) Condensation of glucose and glycine under soil ambient conditions (measurement of optical density) yields of humic substances XANES study of change in speciation of Mn ESR study of Mn speciation in solution 13C CPMAS NMR spectra of FA fraction resembling spectra of natural FAs Jokic et al. (2001b)... 

Figure 15.8. 13C CPMAS NMR spectra of the IHSS Pahokee Peat and a Canadian Grassland (black chernozem) soil and their corresponding humin samples. Reprinted from Simpson, M. J., and Johnson, P. C. E. (2006). Identification of mobile aliphatic sorptive domains in soil humin by solid-state 13C nuclear magnetic resonance. Environ. Toxi. Chem. 25, 52-57, with permission from the Society of Environmental Toxicology and Chemistry.

Fig. 6 Solid-state 13C CP MAS NMR spectra of PVFA-co-PVAm-95/silica hybrid particles (Mn=400,000 g mor1) (a) before cross-linking, and (b) after cross-linking with BICDPM, (c) virtual structure of a BICDPM-functionalized PVFA-co-PVAm network cut out and assignment of the signals in the 13C CPMAS NMR spectra...

Figure 11 The SRI plots of the 13C DDMAS NMR spectra of (A) PMEA (containing 7 wt% water), (B) PHEMA gels (containing 40 wt% water), CPMAS NMR spectra of (C) PMEA, and (D) PHEMA gels against temperature. Suppression temperatures Ts at which respective peaks are most reduced are shown by the arrows. From Ref. 29 with permission.

Figure 24 (A) 13C DDMAS and (B) CPMAS NMR spectra of [3-BC]Ala-labelled bR from...

NMR spectroscopy (31P, II, 13C) and mass spectrometery have been extensively employed for establishing structures of the diazaphospholes. The solid state 13C and 15N CPMAS NMR spectra of 3,5-di-substituted [l,2,4]diazaphospholes have been recorded [78]. Several X-ray crystal structures have been reported for a number of... 

CAL-4 was prepared according to the procedure described in reference 2. Powder XRD confirmed the absence of contaminant phases. 13C MAS NMR spectra were recorded under cross polarization conditions (CPMAS). Single-crystal XRD data were collected at room temperature using MoK radiation. 

Schmidt, M., Knicker, H., Hatcher, P., and Kogel-Knabner, I. (1997a). Improvement of 13C and 15N CPMAS NMR spectra of bulk soils, particle size fractions and organic material by treatment with 10% hydrofluoric acid. Eur. J. Soil Sci. 48,319-328. 

Bisquaric acid was also studied by 13C CPMAS NMR between 123 and 523 K, with powdered crystals.173 This material has also potential for nonlinear optical and dielectric applications. The low-temperature spectra resolve three peaks instead of four in SQA. This compound has no dipole moment, and no phase transition was detected in the studied temperature range, although the lineshape suggests the occurrence of a phase transition below 373 K. An explanation proposed by the authors is the lack of resolution due to the accidental overlapping of the two resonances of the C OH and C — O carbons participating to the HBs, an interpretation also supported by GIAO ab initio chemical shift calculations. 

In the solid, dynamics occurring within the kHz frequency scale can be examined by line-shape analysis of 2H or 13C (or 15N) NMR spectra by respective quadrupolar and CSA interactions, isotropic peaks16,59-62 or dipolar couplings based on dipolar chemical shift correlation experiments.63-65 In the former, tyrosine or phenylalanine dynamics of Leu-enkephalin are examined at frequencies of 103-104 Hz by 2H NMR of deuterated samples and at 1.3 x 102 Hz by 13C CPMAS, respectively.60-62 In the latter, dipolar interactions between the 1H-1H and 1H-13C (or 3H-15N) pairs are determined by a 2D-MAS SLF technique such as wide-line separation (WISE)63 and dipolar chemical shift separation (DIP-SHIFT)64,65 or Lee-Goldburg CP (LGCP) NMR,66 respectively. In the WISE experiment, the XH wide-line spectrum of the blend polymers consists of a rather featureless superposition of components with different dipolar widths which can be separated in the second frequency dimension and related to structural units according to their 13C chemical shifts.63... 

Figure 26 13C CPMAS (A) and DDMAS (B) NMR spectra of [l- 3C]Val-labelled bR from PM. From Ref. 19. The assigned peaks is based on the data of site-directed mutagenesis 85- 87 and REDOR filter experiment.188...

---