Ionic Effects on the Relaxation of NMR Signals

4 Ionic Effects on the Relaxation ofNMR Signals In analogy with the viscosity fi-coefficients, the longitudinal relaxation time of the proton NMR signals of aqueous solutions of electrolytes obeys the Engel and Hertz expression [93]  

A good correspondence exists between the ionic valnes and the ionic 

Values of B for many ions at 25°C are shown in Table 2.11, snpplonented by data from the NMR spin-lattice relaxation of D O molecnles in aqneons salt solutions, again split according to B (K ) = B ,j(Cr). These valnes [127] agree in sign and generally in magnitude with the proton NMR also shown in Table 2.11. 

Ions were classified [93] as being positively hydrated and negatively hydrated according to the signs of their the Gibbs energy of activation for the rate of 

Only aqueous diamagnetic ions can be studied by means of proton NMR measurements of longitudinal relaxation times, T,. Therefore, for paramagnetic ions, for example, transition metal cations, other kinds of NMR measurements are required, but no such data have been found. 

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