: This paper describes 29Si, 27Al, 207Pb and 113Cd NMR studies of Pb- and Cd-exchanged LTA zeolites. The 113Cd NMR spectra identify for the first time two different coordination states for Cd2C in hydrated CdLTA, consistent with x-ray single crystal diffraction data for this zeolite. The effects of Cd2C exchange on the 29Si NMR spectra of LTA are also consistent with the structural data. Cd2C exchange perturbs the 27Al NMR spectrum of the zeolite, as does Pb2C exchange. Changes in the 29Si NMR spectra on Pb2C exchange are explained in terms of structural distortion of the framework. 207Pb NMR spectra of Pb2C exchanged LTA show a single broad signal indicating that Pb2C cations are rigidly located in the zeolite at relatively long Pb—O distances in the hydrated zeolites.

Iron substituted ETS-10 samples with different Fe/Ti ratios were synthesised hydrothermally. The occurrence of a doublet with the isomer shift of octahedral Fe(III) in the Mossbauer spectra.

Lead compounds still have numerous applications in our society, in spite of their known toxicity *. For example they are used in batteries and petroleum additives, paints and housing materials, catalysts and ceramics, glasses and semi-conductors. Elemental analysis will readily show the presence of lead but precise knowledge of the form it takes should be accessible with solid-state 2G7pb NMR, because NMR can probe the local environment of the lead atom(s) 2 ' 8 . The enormous chemical shift range, >15,000 ppm, already established for lead 9 suggests that small changes in its environment will lead to easily detected changes in chemical shift provided that the usual line narrowing techniques developed for solids, such as magic angle spinning (MAS), are successful. On the other hand, distortions from regular geometry around the lead atom will induce large changes in chemical shift anisotropy, and make detection more difficult as has been found for ^H g *0. The aim of this work has been to investigate parameters and variables required for the successful detection of this nucleus which has very favourable properties ( spin 1/2, 21% natural abundance) in the solid state. We have recently shown that 207pj, NM R spectra of solid lead(II) nitrate are significantly and uniformily dependent on temperature ?. Here we present results for some simple lead compounds as well as for model sytems related to soils such as leadexchanged zeolites H