Pair dynamics and the intermolecular nuclear Overhauser effect (NOE) in liquids analysed by simulation and model theories: application to an ionic liquid.
Combining simulation and model theories, this paper analyses the impact of pair dynamics on the intermolecular nuclear Overhauser effect (NOE) in liquids. For the first time, we give a distance resolved NOE. When applied to the ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate the NOE turns out to be of long-range nature. This behaviour translates to the experimentally measured cross- and longitudinal relaxation rates. We were able to calculate the heteronuclear NOE from simulation data, despite the high computational effort. Model theories are computationally less demanding and cover the complete frequency range of the respective spectral density function, they are usually based on a very simple pair distribution function and the solution of the diffusion equation. In order to model the simulated data sufficiently, these simplifications in structure and dynamics have to be generalised considerably.
Department of Computational Biological Chemistry, University of Vienna, Waehringer Strasse 17, A-1090 Wien, Austria.
Sonja
S
Gabl
Department of Computational Biological Chemistry, University of Vienna, Waehringer Strasse 17, A-1090 Wien, Austria.
Christian
C
Schröder
Department of Computational Biological Chemistry, University of Vienna, Waehringer Strasse 17, A-1090 Wien, Austria.
Daniel
D
Braun
Physical Chemistry II, Ruhr-University of Bochum, D-44780 Bochum, Germany.
Hermann
H
Weingärtner
Department of Computational Biological Chemistry, University of Vienna, Waehringer Strasse 17, A-1090 Wien, Austria.
Othmar
O
Steinhauser
D000465:Algorithms; D003198:Computer Simulation; D052578:Ionic Liquids / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D009716:Numerical Analysis, Computer-Assisted; D013113:Spin Labels
D052578:Ionic Liquids; D013113:Spin Labels