Enhanced Solid State NMR Tools for Advanced Research

Solid state NMR investigation is a key tool for the structural characterization of materials, in terms of
coordination/geometry of the active sites as well as identification of cation species among others. Herein,
different research lines all requiring the use of ssNMR facilities are presented. The topics cover a broad
window of research interests going from catalysis to materials science, from energy to sustainability. The
research actually performed at University of Namur is strongly supported by the presence of two
spectrometers a Varian 400MHz and a Bruker 500 MHz. Among the nuclei accessible to the NMR, the most
studied in our facility are those with spin I=1/2, as 13C, 15N, 29Si, 119Sn. However, about 70% of the
nuclei accessible to NMR have are quadrupolar (spin I > ½). These nuclei are characterised by a nonspherical
charge distribution in the nucleus. They experience an electric interaction with surrounding
electric field gradients (EFG), which gives rise to the quadrupolar-coupling interaction Q. Generally, spectra
of quadrupolar nuclei display a very broad resonance lines. High-quality spectra of half-integer quadrupolar
nuclei are typically acquired at very high field, as the linewidth of the central transition is inversely
proportional to the applied magnetic field. Although the study of several quadrupolar nuclei could provide
vital information for our research, the Bruker 500 MHz NMR spectrometer we own has a very limited
spectral width (100 kHz employing digital filters) which rules out the feasibility of such experiments. Hence,
we need a new, more modern spectrometer to broaden the range of the nuclei which can be studied in our
facility.
This project is supported by different research groups in FWB (Federation Wallonie Bruxelles), by the
Technology Platform PC2 (Physico-Chemical Characterization) at UNamur and by the contact group
“Résonance Magnétique Pluridisciplinaire” (RMP) which gather all the expertise in magnetic resonance
within the FWB.