Decomposition of a NMR signal comprising a single resonance in exchange with a Pake doublet: Application to the analysis of 1H NMR spectra of water molecules embedded in synthetic clays

Conventional 1H NMR spectra of water in clays generally consist of several broad overlapping resonances. However, when a type of water is partially oriented, it leads to a Pake doublet superposed to the resonances corresponding to different types of non-oriented water. With the help of a recent method based on nutation experiments, the proportions of the different kinds of water could be determined. Thus, we are able to determine interesting NMR parameters like dipolar couplings, exchange rate, and line broadening. These determinations are complemented by spin relaxation times and self-diffusion measurements which bring additional information about the dynamical behavior of water.