Paramagnetic Mn2+ ions were incorporated in silica gel during the preparation of the sol. Doped silica xerogels were obtained by heat treatment at different temperatures and studied by 29Si and 129Xe nuclear magnetic resonance (NMR) experiments. Comparison between 29Si NMR magic angle spinning (MAS) spectra of doped and undoped xerogels showed that there is a significant effect of the paramagnetic probe on Q2, Q3 and Q4 peaks. Reduction of the 29Si-T1 relaxation time in the presence of the Mn2+ probe was observed. 129Xe NMR spectra were recorded on the xerogels at variable Xe pressures. Results were consistent with 29Si NMR data and confirmed the localization of the paramagnetic probe in surface sites as shown by electron paramagnetic resonance (EPR) of Mn2+.
