Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 8: POSTERS Dynamics and Diffusion
CPP 8.13: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
TD-NMR studies on CuSO4 salt hydrates — •Nikolaus Nestle1, Sebastian Kleinschmidt2, Peter Magin1, and Robert Wengeler1 — 1BASF Aktiengesellschaft, Ludwigshafen — 2Universität Magdeburg, FB Chemie
Despite the high concentration of paramagnetic copper ions, solid CuSO4 hydrates exhibit surprizingly narrow NMR signals. This is known since the late 1940s [1]. Using TD-NMR methods established for polymer studies, the relaxation behaviour of CuSO4 preparations with different water content was studied at room temperature. For the water content of the pentahydrate and below, the NMR signal exhibits a pure solid-state-type magnetization decay behaviour. For slightly overstoichiometric moisture contents, a liquid-like signal is observed in addition to the solid signal. However, the relative amplitudes of the solid and the liquid signal do not mirror the stoichiometric composition of the pentahydrate and the excess water. Instead, the solid signal amplitude only accounts for four hydrate water molecules while the fifth water exhibits rapid exchange with the liquid phase and thus contributes to the liquid-type signal. This finding is in good agreement to results from investigations into the crystal structure of solid CuSO4 pentahydrate [2].
[1] N. Bloembergen, Physica 16, 95-112 (1950). [2] J.J. Rush, J.R. Ferraro, A. Walker, Inorganic Chemistry 6, 346-351 (1967).