Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 48: Poster Session II

MA 48.4: Poster

Donnerstag, 10. März 2016, 15:00–18:00, Poster B1

Theoretical investigations of ¹²⁹Xe NMR in UiO-66 and UiO-67 — •Kai Trepte¹, Jana Schaber², Eike Brunner², and Gotthard Seifert¹ — ¹Technische Universität Dresden, Theoretical Chemistry, Germany — ²Technische Universität Dresden, Bioanalytical Chemistry, Germany

The chemical shift of the isotope ¹²⁹Xe inside the metal organic frameworks (MOFs) UiO-66/UiO-67 (UiO - University of Oslo) has been investigated using density functional theory. Those structures are known for their high thermal and chemical stability [1]. Both MOFs form two types of pores (tetrahedral (T) and octahedral (O) ones), which provide different chemical environments for absorbed Xe atoms. The mentioned isotope of Xe has several advantages in NMR (nuclear magnetic resonance) investigations, as it tends to be mononuclear, chemically inert and has a nuclear spin of I = 1/2. T. Ito and J. Fraissard [2] described the Xe shift inside zeolites as a composition of different influences. Some of these influences are interatomic interactions like Xe-Xe and Xe-surface effects, which can be summed up to gain the total shift. Several model systems have been generated to reduce calculation time and verify this additive behaviour. Additionally, theoretical investigations of Xe inside the crystalline systems allow a separation of the shift as introduced by the different pores. Our results are compared to experimental values to get a deeper insight into the effects on the Xe shift and explain the experimentally observed chemical shift.
Chavan et al., PhysChemChemPhys, 2012, vol.14, pp.1614-1626
T. Ito and J. Fraissard, J. Chem. Phys., vol.76, pp.5225-5229, 1982