ON THE DYNAMICS OF ORGANIC-ZEOLITE INTERACTIONS - TETRAMETHYLAMMONIUM IN SODALITE

The dynamics of tetramethylammonium (TMA) occluded in a beta-cage of zeolite sodalite has been investigated in a comparative molecular dynamics (MD) and n.m.r. (C-13, H-2) study. Concerning deuterium n.m.r., this is the first time that measurements on deuterated organics that are occluded during zeolite synthesis have been performed. The main objective was to understand the dynamics of organic-zeolite interactions on a molecular level, which may enhance to the insight into the role of the organic during zeolite synthesis. MD calculations as was well as solid-state deuterium and cross-polarization magic angle spinning n.m.r. results indicate that TMA occluded in the sodalite beta-cage has a considerable degree of rotational freedom. MD revealed this rotational freedom to be caused mainly by the dynamics of the zeolite lattice; the distance between diametrically opposed oxygen atoms in the beta-cage was found to fluctuate by as much as 0.4 angstrom.