Magnetization-exchange spectra

Fig. 12. The magnetization-exchange experiment.(a) magnetization-exchange pulse sequence (b) = 3 C magnetization-exchange spectra of doubly C-labelled zinc acetate at different mixing times Tm (c) simulated (solid lines) and experimental ( ) magnetization-exchange curves on (top) and off (bottom) the R condition. (Parts (b) and (c) reproduced from ref. 75, 1988, with permission from Elsevier Science.)...

Fig. 16. Two-dimensional magnetization-exchange spectra of a SBR recorded with different mixing times have been used = 2.5 ms (a), 5 ms (b), 15 ms (c), and 30 ms (d). The 2D surface representation for = 30 ms in (e) shows that all cross-peaks are positive. Reproduced from Ref. 65, with permission from American Institute of Physics.

Fig. 3.60 Proton magnetic resonance spectrum of pyrogallol (AB2) in DjO solution reference DSS, and sweep width 500 Hz. Inset sweep ofTset 380 Hz, sweep width 50 Hz. The signal at <5 5 is due to HOD and arises from exchange of the three phenolic hydrogens with the solvent.

Figure 2 shows the proton magnetic resonance spectrum for moxalactam disodium. The spectrum was recorded on a 60 MHz instrument. An interpretation of the spectrum is presented in Table 2. The spectrum is complex, for the configuration at site a undergoes rapid equilibrium and the proton at a is exchanged with deuterium. At high resolution such as at 360 MHz every resonance is split except for that of HQ. 

Aksnes, D.W., Hutchison, S.M. and Packer, K.J. (1968) Nuclear spin relaxation and chemical exchange effects in the 19F nuclear magnetic resonance spectrum of the hexafluoroniobate ion. Mol. Phys., 14, 301-309. 

Fig. 10. Calculated nuclear magnetic resonance spectrum of two interacting spin 4 nuclei with a relative chemical shift 28 and a coupling strength J, plotted as a function of the deviation A of the frequency of the driving field from the average frequency of the two nuclei. The spectrum is symmetric around, 4 = 0 and only the positive half is shown. The spectra are for R = <7/8 = 1 and for several values of the exchange rate T = 1/rJ (Alexander, 1962).

---