Nuclear Magnetic Resonance in Heterogeneous Catalysis

Abstract

Magnetic resonance includes both nuclear and electron magnetic resonances. The former applies to nuclei that have nonzero nuclear magnetic moments, the latter to unpaired electrons that all have the same electron magnetic moment. Laws that govern these techniques are quite similar; they differ only on the quantitative scale simply because the largest nuclear magnetic moment (that of the proton) is far smaller than that of the electron (the ratio is 1840). Table 5.1 gives the nuclear spin from which the nuclear magnetic moment derives, as a function of the parity of the mass and atomic number; the angular moment is expressed in ħ = h/2π units. The natural abundance, the relative sensitivity (compared to that of the proton), and the quadrupolar moment (where appropriate) of a limited selection of nuclei often encountered in catalysis are listed in Table 5.2.