This research involves pillared clays and related complex layered oxides which are a novel class or two-dimensional microporous solids which hold great promise for applications in catalysis and molecular separations. The research is co-funded between the Division of Materials Research and the Division of Chemistry. Important issues include mechanisms by which guest species access the 2nd microporous structure. The influence of geometrical properties and chemical reactivity of the guest-host systems are being synthesized and characterized. These include metal oxide pillared clays, sol-clay complexes, super gallery clays, tubular silicate-layered complexes, pillared layered double hydroxides, and pillared layered silicic acids. The fundamental physics of these materials is being investigated theoretically and experimentally. Methods include gated picosecond pulsed Raman Spectroscopy, 2d diffusion and adsorption, elastic and inelastic neutron scattering diffuse and discrete x-ray diffraction, NMR and FTIR absorption.