Understanding the ionic liquid [NC4111][NTf2] from individual building blocks: an IR-spectroscopic study
Kenny Hanke1, Matin Kaufmann, Gerhard Schwaab
1Department of Physical Chemistry II, Ruhr-University Bochum, D-44801 Bochum, Germany. martina.havenith@rub.de.
Physical Chemistry Chemical Physics : PCCP
|March 10, 2015
Summary
This study investigates ionic liquid interactions using mass-selective spectroscopy. The findings reveal antiparallel packing in neutral ion pairs and discuss binding sites in charged ionic liquid clusters.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Ionic Liquids
Background:
- Ionic liquids (ILs) exhibit complex interactions influencing their bulk properties.
- Understanding these interactions at the molecular level is crucial for designing ILs with specific functionalities.
Purpose of the Study:
- To elucidate the underlying interactions governing the IR spectra of [NC4111][NTf2] and its deuterated isotopomer.
- To investigate the structural and electronic properties of neutral and charged ionic aggregates.
Main Methods:
- Mass-selective Coherent Ion-Polarization spectroscopy (CIVP) to isolate ionic building blocks.
- Superfluid helium droplets and solid neon matrices for spectral recording.
- Polarization-dependent band intensity analysis in external electric fields.
Main Results:
- Cluster spectra generally resemble bulk spectra, with (2,2) systems showing the closest similarity.
- Neutral ion pairs exhibit an antiparallel packing structure at low temperatures.
- Charged IL clusters present additional binding sites not observed in the bulk phase.
- Conformational changes, including cis isomer population, observed in higher clusters.
Conclusions:
- Interactions in ionic liquid clusters are consistent with minimal hydrogen bonding.
- The study provides insights into the structure and dynamics of ionic liquid aggregates.
- The findings contribute to a fundamental understanding of ionic liquid behavior.
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