Coupling between Protons and

Consider Spectrum 6.9 which shows a CHCI3 singlet plotted at very high intensity. 

Spectrum 6.9 CHCl3 singlet plotted at high intensity. 

13 C satellites can actually be quite useful sometimes, as they give a ready-made visual comparator for the quality of spectrometer high-order shimming and for trace impurities that you may be trying to quantify, since we know that each satellite will have an intensity of 0.55 % of the peak it is associated with. 

Two final interesting points relating to 13C satellites... Whilst they are generally, evenly spaced on either side of the major peak, they do not have to be exactly symmetrically disposed about it. It is 

13C coupling has very little significance in everyday proton NMR interpretation, though it has been used in the past to crack specific problems by means of selective enrichment of a specific carbon during synthesis, with a greater than normal percentage of 13C isotope, which makes detection easy. 

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Figure 6 X-half filters used for filtering or selecting 13C and 15N-attached protons. Thick and thin closed rectangles are 180° and 90° pulses, respectively, open rectangles are spin lock pulses. (A) A simple X-half filter (2). The delay t is equal to 0/(2[1JXH]) where 1JXH is the one-bond coupling between proton and either 13C (120 to 140 Hz) or 15N (95 Hz). The second 90° pulse is the editing...

In reality, this behavior is only observed in the limit of small jg. At currents o 1 A cm-2 that are relevant for fuel cell operation, the electro-osmotic coupling between proton and water fluxes causes nonuniform water distributions in PEMs, which lead to nonlinear effects in r/p M- These deviations result in a critical current density, p at which the increase in r/pp j causes the cell voltage to decrease dramatically. It is thus crucial to develop membrane models that can predicton the basis of experimental data on structure and transport properties. 

The magnitude of scalar spin-spin coupling between protons and Li is again rather small (< 1 Hz), except in hydrido complexes where fairly large values of y( Li, H) have been reported in two cases (5, 7=8.4 Hz [117], 6, J= 10.5 Hz... 

An observation of spin-spin coupling between proton and fluorine by 19F NMR and/or 1H NMR would be the most direct and convincing evidence. However, there has been only one report on such H—F spin-spin couplings in the compound 3, and only a few reports described broadening of the spectra. Meanwhile, the interaction of metal with organic fluorine (M- -F—C) with spin-spin coupling has often been reported (Scheme 4.2) [10,17-19]. Dynamic interaction of organic fluorine with a metal species has been summarized well in Ref. [17],... 

Couplings between protons and the other commonly studied magnetic nuclei ( F, are continually being found and correlated. 

HETCOR spectrum of 2-methyl-3-pentanone. A HETCOR spectrum indicates coupling between protons and the carbons to which they are attached. 

It must be realized that the effect of spin-spin coupling of protons to other magnetic nuclei may be observed in the proton spectra, and hence some idea of the magnitudes of coupling between protons and some commonly occurring magnetic nuclei may be useful in interpreting proton spectra. 

Upon the transition from primary polymer architectures to secondary structural units at the mesoscopic scale interactions of solvent-solvent, solvent-polymer, polymer-polymer types are renormalized into effective interactions between sidechains and aqueous domains, as indicated in Fig. 3. These interactions control proton distribution and mobilities as well as the coupling between proton and water transport. At the mesoscopic level of the theory, the hydrophobic polymer phase formed by the backbones can already be considered as an inert, structureless matrix. 

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