6 Li und 7 Li MAS-NMR-spektroskopische Untersuchungen an ternären und quaternären Lithiummagnesiumchloriden sowie Röntgen- und Neutroneneinkristall-Untersuchungen an Iodaten und Periodaten von zweiwertigen Metallen

The major part of this thesis deals with 6 Li solid state spectroscopic investigations of ternary and quaternary lithium magnesium chlorides. The 6 Li MAS-NMR spectres show two separate signals in accordance with the two different sites of the Li ions in an inverse spinel structure. Due to comparative 6 Li MAS-NMR spectroscopic measurements of 6 Li 2 ZnCl 4 (Li occupies only the octahedral 16d sites) and of the lithium deficient compounds Li 2-2x Mg 1+x Cl 4 , Li 2-x Cu x MgCl 4 and Li 2-x Na x MgCl 4 the signal 1 with a chemical shift of 1.2 ppm can be assigned to the tetrahedral co-ordinated 8a site and signal 2 with a chemical shift of 0.3 ppm to the octahedral co-ordinated 16d site in an inverse spinel type. 6 Li MAS NMR spectra including 1D-EXSY experiments have been recorded and are discussed with respect to the dynamics of the tetrahedral co-ordinated lithium ions in Li 2 MgCl 4 and the activation energy could be determined to 6.6 kJ/mol. This can be ascribed to a local motion of the Li ions within a tetrahedral site. Neutron diffraction experiments of Co(IO 3 ) 2 ⋅4H 2 O single crystals are carry out in order to allow a more detailed interpretation of IR- and Raman-data. This exhibits that the interaction of the layered structure is not caused by hydrogen bonds but by interionic I-O-interactions with a I-O(1) distance of 277.9(1) ppm. Furthermore the structures of Li 1,25 Cd 1,67 In 0,48 Cl 6 , Li 0,24 Mn 1,71 In 0,78 Cl 6 , (NH 4 ) 21 [H 3 Mo 51 (MoNO) 6 V 6 O 183 (H 2 O) 18 ]⋅53H 2 O, Cd 0,967 Ga 0,022 Cr 2 Se 4 und Pd(S 2 CN(C 5 H 11 ) 2 ) 2 could be determined by both X-ray and neutron-diffraction experiments.