• search hit 48 of 95
Back to Result List

Influence of imidazolium bis(trifluoromethylsulfonylimide)s on the rotation of spin probes comprising ionic and hydrogen bonding groups

  • The influence of the alkyl chain length in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide)s is studied to explore the rotation of piperidine-1-yloxyl derivatives substituted with either hydrogen bonding hydroxy group or ionic substituents, such as the cationic trimethylammonium or the anionic sulfate group placed at the 4 position. Structural variation of the ionic liquids results in differences of their viscosity influencing the rotation of the spin probes. The size of the average rotational correlation times of the spin probes dissolved in the ionic liquids depends further on the additional substituent in 4-position at these spin probes. The rotational correlation time exhibits a linear dependence on the ionic liquid viscosity in the case of the spin probe forming hydrogen bonding with the ionic liquids. In contrast to this, a deviation from the Stokes-Einstein behavior is found in the case of rotation of the charged spin probes in the 1-alkyl-3-methylimidazolium bis( trifluoromethylsulfonylimide) s substituted with aThe influence of the alkyl chain length in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide)s is studied to explore the rotation of piperidine-1-yloxyl derivatives substituted with either hydrogen bonding hydroxy group or ionic substituents, such as the cationic trimethylammonium or the anionic sulfate group placed at the 4 position. Structural variation of the ionic liquids results in differences of their viscosity influencing the rotation of the spin probes. The size of the average rotational correlation times of the spin probes dissolved in the ionic liquids depends further on the additional substituent in 4-position at these spin probes. The rotational correlation time exhibits a linear dependence on the ionic liquid viscosity in the case of the spin probe forming hydrogen bonding with the ionic liquids. In contrast to this, a deviation from the Stokes-Einstein behavior is found in the case of rotation of the charged spin probes in the 1-alkyl-3-methylimidazolium bis( trifluoromethylsulfonylimide) s substituted with a longer alkyl chain. This effect may be explained by phase separation on a molecular level between the charged part of the ionic liquid and the longer alkyl chains bound at the imidazolium ion. Although the neutral and the cationic spin probes show only a slight dependence between ionic liquid structure variation and the hyperfine coupling constants, structural effects cause changes in the hyperfine coupling constants in the case of the anionic spin probes. These probes strongly interact with the imidazolium ion.show moreshow less

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Metadaten
Author:Veronika StrehmelORCiDGND, Hans Rexhausen, Peter Strauch
URL:http://www.rsc.org/Publishing/Journals/CP/index.asp
DOI:https://doi.org/10.1039/B920586a
ISSN:1463-9076
Document Type:Article
Language:English
Year of first Publication:2010
Year of Completion:2010
Release Date:2017/03/25
Source:Physical chemistry chemical physics. - ISSN 1463-9076. - 12 (2010), 8, S. 1933 - 1940
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie
Peer Review:Referiert