Proton spectroscopy, high-resolution

Vinogradov E, Madhu PK, Vega S (2005) Strategies for High-Resolution Proton Spectroscopy in Solid-State NMR. 246 33-90... 

NMR provides one of the most powerful techniques for identification of unknown compounds based on high-resolution proton spectra (chemical shift type integration relative numbers) or 13C information (number of nonequivalent carbon atoms types of carbon number of protons at each C atom). Structural information may be obtained in subsequent steps from chemical shifts in single-pulse NMR experiments, homo- and heteronuclear spin-spin connectivities and corresponding coupling constants, from relaxation data such as NOEs, 7) s 7is, or from even more sophisticated 2D techniques. In most cases the presence of a NOE enhancement is all that is required to establish the stereochemistry at a particular centre [167]. For a proper description of the microstructure of a macromolecule NMR spectroscopy has now overtaken IR spectroscopy as the analytical tool in general use. 

Characterization of the solid phases Si, A1 and Na contents were determined by proton-induced Y-ray emission (PIGE) (11,57) or by high resolution solid state i—NMR spectroscopy (49,50,58)... 

Infrared spectroscopy has been used for quantitatively measuring the amounts of 1,2-, 3,4-, cis-1,4-, and trans-1,4-polymers in the polymerization of 1,3-dienes its use for analysis of isotactic and syndiotactic polymer structures is very limited [Coleman et al., 1978 Tosi and Ciampelli, 1973]. Nuclear magnetic resonance spectroscopy is the most powerful tool for detecting both types of stereoisomerism in polymers. High-resolution proton NMR and especially 13C NMR allow one to obtain considerable detail about the sequence distribution of stereoisomeric units within the polymer chain [Bovey, 1972, 1982 Bovey and Mirau, 1996 Tonelli, 1989 Zambelli and Gatti, 1978],... 

Chemical shift correlated NMR experiments are the most valuable amongst the variety of high resolution NMR techniques designed to date. In the family of homonuclear techniques, four basic experiments are applied routinely to the structure elucidation of molecules of all sizes. The first two, COSY [1, 2] and TOCSY [3, 4], provide through bond connectivity information based on the coherent (J-couplings) transfer of polarization between spins. The other two, NOESY [5] and ROESY [6] reveal proximity of spins in space by making use of the incoherent polarization transfer (nuclear Overhauser effect, NOE). These two different polarization transfer mechanisms can be looked at as two complementary vehicles which allow us to move from one proton atom of a molecule to another proton atom this is the essence of a structure determination by the H NMR spectroscopy. 

D. Morvan, A. Demidem, J. Papon, M. De Latour and J. C. Madelmont, Melanoma tumors acquire a new phospholipid metabolism phenotype under cystemustine as revealed by high-resolution magic angle spinning proton nuclear magnetic resonance spectroscopy of intact tumor samples, Cancer Res., 2002, 62, 1890-1897. 

Sims CJ, Fujito DT, Burholt DR, Dadok J, Giles HR, Wilkinson DA (1993) Quantification of human amniotic fluid constituents by high resolution proton nuclear magnetic resonance (NMR) spectroscopy. Prenat Diagn 13 473-480... 

The continued development of high-resolution NMR spectroscopy indicates the value of these instruments and the importance of this technology in future chemical research. Proton f H) detected NMR spectra are the easiest to obtain and can be acquired with just a few micrograms of sample. Since carbon forms the backbone of organic structures, carbon (13C) NMR is also important in structural studies. For this reason, H NMR, 13C NMR, and 2D techniques involving these two nuclei are widely used in the characterization of unknown natural products. 

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