2D NMR spectroscopy

Morris K F and Johnson C S Jr 1993 Resolution of discrete and continuous molecular size distributions by means of diffusion-ordered 2D NMR spectroscopy J. Am. Chem. See. 115 4291-9... 

In S-N compounds containing H bonded directly to nitrogen, inverse detection 2D NMR spectroscopy can be applied to give N... 

How many types of plots are generally used in 2D NMR spectroscopy ... 

The sine-bell, sine-bell squared, phase-shifted sine-bell, and phase-shifted sine-bell squared window functions are generally used in 2D NMR spectroscopy. Each of these has a different effect on the appearance of the peak shape. For all these functions, a certain price may have to be paid in terms of the signal-to-noise ratio, since they remove the dispersive components of the magnitude spectrum. This is illustrated in the following COSY spectra ... 

Before the advent of 2D NMR spectroscopy, the classical procedure for determining proton-proton connectivities was by homonuclear proton spin decoupling experiments. Such experiments can still serve to determine some H/ H connectivities in simple molecules. 

A more useful type of 2D NMR spectroscopy is shift-correlated spectroscopy (COSY), in which both axes describe the chemical shifts of the coupled nuclei, and the cross-peaks obtained tell us which nuclei are coupled to which other nuclei. The coupled nuclei may be of the same type—e.g., protons coupled to protons, as in homonuclear 2D shift-correlated experiments—or of different types—e.g., protons coupled to C nuclei, as in heteronuclear 2D shift-correlated spectroscopy. Thus, in contrast to /-resolved spectroscopy, in which the nuclei were being modulated (i.e., undergoing... 

Fig. 8. Pulse schemes for 2H 2D NMR spectroscopy of weakly ordered, deuterated solutes (a) 2H Q-COSY, (b) 2H-13C HETCOR experiment with 13C decoupling, (c) 2H-2H COSY 2D experiment. (Reproduced by permission of American Chemical Society.)...

The examples described in this chapter are meant to illustrate the actual application of NMR for the study of protein-ligand interactions in the pharmaceutical industry. In our group, the focus has been mainly on protein observe techniques, as we have been fortunate enough to have a dedicated laboratory for providing both unlabeled and labeled proteins in large quantities. At present, two-dimensional HSQC spectra offer the highest content of information which is not accessible that rapidly by other methods. 2D NMR spectroscopy provides... 

Mahmood A, Fatima I, Kosar S, Ahmed R, Malik A. (2010) Structural determination of prunusins A and B, new C-alkylated flavonoids from Prunus domestica by ID and 2D NMR spectroscopy. Magn Reson Chem 48 151-154. 

Stephan H, Freund S, Meyer JM, Winkelmann G, Jung G (1993) Structure Elucidation of the Gallium-Omibactin Complex by 2D-NMR Spectroscopy. Liebigs Ann Chem 43... 

The structure and relative configuration of six new dolabellanes (30-35) isolated from the soft coral Clavularia inflata collected at Orchid Island located 44 nautical miles off Taiwan s southeast coast is depicted in Fig. 4 [16]. The relative configuration was assigned based on ID and 2D NMR spectroscopy and supports the cis arrangement between the isopropyl group at... 

Four cyanidin 4 -glucosides have recently been isolated from pigmented scales of red onion. These structures were established by extensive use of 2D NMR spectroscopy and electrospray LC MS. The previous report on 4 -glucosyl linkages in two anthocyanins from... 

H NMR spectroscopy was used to deduce the tram configuration of the dihydrotriazolopyrimidinone substituents from the /h,h coupling constants (11 ppm) of the respective protons (88JHC173). 2D NMR spectroscopy was used to identify the two isomers 341 and 343 (89H239). 

In a chapter regarding 2D NMR spectroscopy of paramagnetic molecules, the obvious perspective is that of using three-dimensional (3D) NMR for paramagnetic molecules. The demand for 3D spectroscopy is based on a need of increased resolution when macromolecules are concerned. It is possible that for small complexes 3D spectroscopy will never be necessary. However, every time something new has appeared in science, the majority has reacted by saying that the utility was scarce in their own field, and the majority has not always been right. Therefore, we do not commit ourselves. 

Enol (104), generated rapidly in acidic solution from a precursor acetal, shows remarkable stability fi/2 > 3 h in 0.1 mol dm-3 DC1 in CD3OD at 300 K, allowing its characterization by 2D NMR spectroscopy. A DFT study of a simple model, 2,2-difluoroethenol, indicates that there are significant differences in timing of the protonation TS compared with the non-fluorinated enol.288... 

Hsu, P. H., and Hatcher, P. G. (2005). New evidence for covalent coupling of peptides to humic acids based on 2D NMR spectroscopy A means for preservation. Geochim. Cosmochim. Acta 69,4521 1533. 

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