Nuclear magnetic resonance spectroscopy chemical shift

Hodson, J., The Estimation of the Photodegradation of Organic Compounds by Hydroxyl Radical Reaction Rate Constants Obtained from Nuclear Magnetic Resonance Spectroscopy Chemical Shift Data, Chemosphere, 17, 2339-2348 (1988). 

Hodson, J. 1988. The estimation of the photodegradation of organic compounds by hydroxyl radical reaction rate constants obtained from nuclear magnetic resonance spectroscopy chemical shift data. Chemosphere 17 2339-2348. 

NMR spectra. See also nuclear magnetic resonance spectroscopy chemical shifts, 573-574 interpretation, 571-573 spin-spin coupling, 574-576 IMS, 582 halide ion, 637 haloform reaction, 403-408 benzoic acid synthesis, 405-406 p-methoxybenzoic acid, 406-407 semimicroscale preparation, 407 08 halogenation... 

In earlier literature reports, x-ray data of a-based ceramics, the /3-like phase observed in certain silica minerals was explained by a structural model based on disordered Q -tridymite. However, others have suggested that the structure of the stabilized jS-cristobalite-like ceramics is closer to that of a-cristobalite than that of Q -tridymite, based on the 29Si nuclear magnetic resonance (NMR) chemical shifts (Perrota et al 1989). Therefore, in the absence of ED data it is impossible to determine the microstructure of the stabilized jS-cristobalite-like phase. ED and HRTEM have provided details of the ceramic microstructure and NMR has provided information about the environments of silicon atoms in the structure. Infrared spectroscopy views the structure on a molecular level. 

Cockerill AF, Davies GLO, Harden RC and Rackham DM (1973) Lanthanide shift reagents for nuclear magnetic resonance spectroscopy. Chemical Reviews 73 553-588. 

Nuclear Magnetic Resonance Spectroscopy. Nmr is a most valuable technique for stmeture determination in thiophene chemistry, especially because spectral interpretation is much easier in the thiophene series compared to benzene derivatives. Chemical shifts in proton nmr are well documented for thiophene (CDCl ), 6 = 7.12, 7.34, 7.34, and 7.12 ppm. Coupling constants occur in well-defined ranges J2-3 = 4.9-5.8 ... 

The value of H n.m.r. spectroscopy in determining the structures of carbohydrates is well recognized. In this Section, some of the important features observed in the 100-MHz, H n.m.r. spectra of sucrose derivatives will be discussed, and the potential of I3C nuclear magnetic resonance spectroscopy will be very briefly indicated. Horton and his colleagues162 discussed the high resolution, 4H n.m.r. spectra of octa-O-acetylsucrose (75). The chemical shifts and cou-... 

To detect dynamic featnres of colloidal preparations, additional methods are required. Nuclear magnetic resonance spectroscopy allows a rapid, repeatable, and noninvasive measurement of the physical parameters of lipid matrices withont sample preparation (e.g., dilution of the probe) [26,27]. Decreased lipid mobility resnlts in a remarkable broadening of the signals of lipid protons, which allows the differentiation of SLN and supercooled melts. Because of the different chemical shifts, it is possible to attribute the nuclear magnetic resonance signal to particnlar molecnles or their segments. 

In an attempt to relate calculated results to experimental findings for monomeric, lignin model compounds, preliminary work has compared theoretically determined electron densities and chemical shifts reported from carbon-13 nuclear magnetic resonance spectroscopy (62). Although chemical shifts are a function of numerous factors, of which electron density is only one, both theoretical and empirical relationships of this nature have been explored for a variety of compound classes, and are reviewed by Ebra-heem and Webb (63), Martin et al. (64), Nelson and Williams (65), and Farnum (66). 

Some attempt has been made to establish relationships between chemical shifts, measured by nuclear magnetic resonance spectroscopy and redox potential data.42... 

Physical phenomena other than rates and equilibrium constants can be correlated by Hammett-type relationships. For example, as Figure 2.4 shows, in 13C nuclear magnetic resonance spectroscopy (called Cmr) the chemical shift of the cationic carbon in 17 is correlated by Brown s cr + values.21 And the C=0... 

Hawkes, G.E., Smith, R.A., and Roberts, J.D., Nuclear magnetic resonance spectroscopy carbon-13 chemical shifts of chlorinated organic compounds, J. Org. Chem., 39, 1276, 1974. 

DuVernet, R. and Boekelheide, V., Nuclear magnetic resonance spectroscopy ring-current effects on carbon-13 chemical shifts, Proc. Natl. Acad. Sci. U.S.A., 71, 2961, 1974. 

Srinivasan, P.R. and Lichter, R.L., Nitrogen-15 nuclear magnetic resonance spectroscopy evaluation of chemical shift references, J. Magn. Reson., 28, 227, 1977. 

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