The structural and dynamic properties of 1‐bromodecane in urea inclusion compounds investigated by solid‐state 1H, 13C and 2H NMR spectroscopy

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 (1)H and (13)C 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 (2)H 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.