Search

HPM-2 is a new organosilicate layeredmaterial synthesized by thefluoride route using 2-ethyl-1,3,4-trimethylimidazolium. The layersare of a new structural type (denoted mtf) and are held together bystrong hydrogen bonds giving rise to a 1H magic angle spinning(MAS) nuclear magnetic resonance (NMR) at around 16 ppm and by Coulombicinteractions between silanolates and the organic cations residingin the interlayer space. Upon calcination HPM-2 transforms into thepure silica MTF zeolite by topotactic condensation, a process thatis essentially completed at 400 °C. Attempts to apply known methodsto derive new materials (swelling, delamination, interlayer expansion)are described. In the case of the interlayer expansion reaction, anonmicroporous dense phase is obtained, which is likely due to anunfavorable disposition of silanols in close couples within each layer.Silanol condensation between the newly incorporated silicon speciesoccurs across the main window producing narrower (6 member ring, 6MR)rather than wider (10MR) windows. [ABSTRACT FROM AUTHOR]