Use of Fourier Maps to Study High Pressure Guest Insertion and Polymerization in Zeolites

Zeolites represent an important family of porous materials based on corner sharing TO4 (T=Al, Si,...) tetrahedra. The microporous nature of these materials allows insertion of a great variety of guest atoms, ions or molecules giving rise to a large number of technological applications in catalysis, molecular sieves and ion-exchange materials. High pressure can be used to completely fill the subnanometric pores with guest molecules, thereby strongly modifying the mechanical, electrical and optical properties of the host zeolite. In the case of simple organic molecules, polymerization can be induced under high pressure eventually with the aid of UV irradiation to produce novel nanocomposite materials, which can be recovered at ambient pressure. Insertion of guest molecules (H2O, CO, CO2, C2H2, C2H4, Ar) in different hydrophilic and hydrophobic AlPO4 and SiO2 zeolite-type materials was studied by single crystal and powder x-ray diffraction using both synchrotron and laboratory sources [1-4]. The guest molecules present significant disorder and Fourier maps provide important information on the distribution of guests in the pores. In the case of zeolite/polymer nanocomposites, Fourier maps can be used to characterize the translational, orientational and occupational disorder of the isolated polymer chains, which have a strong influence on the properties of the nanocomposite. 1. J. Haines, O. Cambon, C. Levelut, M. Santoro, F. Gorelli, G. Garbarino, J. Am. Chem. Soc. 2010, 132, 8860. 2. M. Santoro, F. A. Gorelli, R. Bini, J. Haines, and A. van der Lee, Nature Commun ., 2013, 4, 1557. 3. D. Scelta, M. Ceppatelli, M. Santoro, R. Bini, F. A. Gorelli, A. Perucchi, M. Mezouar, A. van der Lee, J. Haines, Chem. Mater., 2014 , 26, 2249. 4. F. G. Alabarse, J. Rouquette, B. Coasne, A. Haidoux, C. Paulmann, O. Cambon, J. Haines, J. Am. Chem. Soc., 2015, 137, 584.