Chemical shift overview

Figure 2.1 provides a quick overview of the basic chemical shift ranges for carbon-bound F, CF2, and CF3 substituents. Specific details... 

FIGURE 2.1. Overview of Fluorine Chemical Shifts (relative to CFC13 (8 = 0))... 

We will now proceed to provide an overview of chemical shift effects of 29Si when framework elements other than silicon and oxygen are present in zeolites. 

II. PROTON CHEMICAL SHIFTS IN GRIGNARD REAGENTS A. Overview... 

Overviews of theoretical calculations of chemical shifts using salicylaldehydes are given . In these papers a large number of methods and basis sets are tested. 

The traditional ways of evaluating the IHB characteristics are to assess the vibrational frequencies or intensities of the OH stretching or torsion in the IR spectra and the chemical shifts of the hydroxyl protons in the NMR spectra which are found to be nicely correlated ". Crystal-structure analysis also provides essential information in this field. Bilton and coworkers carried out a systematic survey of the internally hydrogen-bonded frames in the 200,000 structures of the CSD and gave a general overview of the IHB in the solid state. 

In 1995 Oldfield reviewed the applications of ab initio methods to chemical shift structure refinement, with special emphasis on the construction of chemical shift hyper-surfaces 3(y>, yf) for proteins, de Dios further discussed the range of ab initio calculations using NMR chemical shifts, focussing on the construction of computed chemical shift hyper-surfaces for proteins. In a more recent review, Ando et alf presented an overview of the interplay... 

An overview of Se chemical shift ranges shows that this parameter is strongly dependent on the electronegativity of X. This is exemplified in Fig. 1 for C-Se-X fragments. However, individual molecular structures may cause variations of several hundreds of ppm. 

In addition to the J-resolved experiments several other enhanced chemical shift correlated experiments are available for determining coupling constants. A short overview and classification is given in Table 5.8. Some experiments like the P.COSY or E.COSY experiment are explained in more detail in section 5.4.1.1. 

An overview of the recent progress in the theoretical calculations of Co chemical shielding tensors has been given. It is encouraging that the DFT approach is useful for rationalizing the entire Co chemical shift range of Co(III) complexes. It is desirable to pursue a more accurate description of the... 

---