Host–Guest Silicalite-1 Zeolites: Correlated Disorder and Phase Transition Inhibition by a Small Guest Modification

We have investigated the nature and extent of nanoscale disorder in prototypical host–guest zeolites, made silicalite-1 (host) organic structure-directing agent (OSDA, guest). The four different selected OSDA-silicalite-1 differ in: mineralizing used (F– vs OH–), synthesis method (hydrothermal solvent-free), OSDA (tetrapropylammonium (TPA) tripropylethylammonium TPEA). comparison between TPA TPEA, chemically similar but differing their symmetry, is examined great detail owing to novel relationship found geometrical monoclinic–orthorhombic (m–o) phase transition occurring at low temperatures. Long- short-range organization ordering are characterized by complementary X-ray diffraction (XRD), Raman analysis, multinuclear NMR spectroscopy (13C, 14N, 29Si). possibility m–o studied all these techniques variable T values. An in-depth study carried out structure determination two-dimensional (2D) 29Si–29Si INADEQUATE correlations, including an up-to-date analysis anisotropic atomic displacement parameters a new fitting approach estimate correlated from 2D data sets. collected results allow us demonstrate how created positioning less symmetric TPEA guest leads for half atom sites host framework that completely inhibits transition.