ANOMALOUS MOBILITY OF MOLECULES, STRUCTURE OF THE GUEST SUBLATTICE, AND TRANSFORMATION OF TETRANATROLITE TO PARANATROLITE

The structure of the guest sublattice in the structural channels of na trolite zeolites oversaturated with water (also, at high pressures) is established. It was found from H-1 NMR spectra that reduction of symm etry and sharply increased mobility of water molecules in paranatrolit e and in the high-pressure phase of orthorhombic natrolite follow the same mechanism - half of positions in the structural channels are occu pied by ordered water molecules. The other positions are vacant and ma y be involved in the mechanism of fast diffusion of water molecules.