The structural and dynamic properties of 1‐bromodecane in urea inclusion compounds investigated by solid‐state 1H, 13C and 2H NMR spectroscopy |
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Authors: | Xiaorong Yang Klaus Müller |
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Institution: | Institut für Physikalische Chemie, Universit?t Stuttgart, Pfaffenwaldring 55, D‐70569 Stuttgart, Germany |
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Abstract: | For asymmetric guest molecules in urea, the end‐groups of two adjacent guest molecules may arrange in three different ways: head–head, head–tail and tail–tail. Solid‐state 1H and 13C NMR spectroscopy is used to study the structural properties of 1‐bromodecane in urea. It is found that the end groups of the guest molecules are randomly arranged. The dynamic characteristics of 1‐bromodecane in urea inclusion compounds are probed by variable‐temperature solid‐state 2H NMR spectroscopy (line shapes, spin–spin relaxation: T2, spin‐lattice relaxation: T1Z and T1Q) between 120 K and room temperature. The comparison between the simulation and experimental data shows that the dynamic properties of the guest molecules can be described in a quantitative way using a non‐degenerate three‐site jump process in the low‐temperature phase and a degenerate three‐site jump in the high‐temperature phase, in combination with the small‐angle wobbling motion. The kinetic parameters can be derived from the simulation. Copyright © 2011 John Wiley & Sons, Ltd. |
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Keywords: | solid‐state NMR 1H 13C and 2H structure and dynamics 1‐bromodecane urea inclusion compounds |
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