NMR spectra chemical shifts

However, the situation is much less complex for NMR spectra. Whereas measurement conditions may have a high impact on NMR spectra, chemical shift... 

Parameters for the calculation of chemical shift in nmr spectra. Chemical shifts in nmr spectra. 

Table 1. Structural carbon distribution (%) of the humic acids extracted from soil horizons, adopted from Xing (2001). The distribution was calculated from solid state 13C Cross-Polarization Magic-Angle-Spinning (CP/MAS) NMR spectra. Chemical shift assignment for carbon functional groups alkyl 0-50 ppm O-alkyl 50-117 ppm aromatic 107-165 ppm.

Note that in the context of exchange effects on NMR spectra chemical shift differences must be measured... 

Fig. 5.44 Calculated and experimental H and 13C NMR spectra chemical shifts relative to TMS H and C, respectively. The calculations were done on the B3LYP/6-31G geometry (B3LYP is a density functional method Chapter 7) at the HF/6-311+G(2d,p) and HF/6-31G levels using the default NMR method (GIAO) implemented in Gaussian 94W [198]. The experimental values are from ref. [235], except for the values for [7]paracyclophane [307]. The larger basis set may be somewhat more accurate but takes longer. Compare with Chapter 7, Fig. 7.9...

All synthesized ACTS copolymers are completely soluble in usual organic solvents. The structure of copolymers was proved by the data of ultimate analysis, NMR and 29Si NMR spectra, chemical shifts of which are shown in Table 10. 

Figve 13.5. Nmr spectra chemical shift, (a) Toluene (b) p-xylene (c) mesityiene. 

---