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From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Halogen bonding in iodo-perfluoroalkane/pyridine mixtures
Haiyan Fan1, Jeffrey K Eliason, C Diane Moliva A
1Department of Chemistry, Concordia College, Moorhead, Minnesota 56562, USA.
The Journal of Physical Chemistry. A
|December 4, 2009
Summary
This study used noisy light-based coherent anti-Stokes Raman scattering (I((2)) CARS) spectroscopy to investigate halogen bonding between iodo-perfluoroalkanes and pyridine. The research found that pyridine
Area of Science:
- Supramolecular Chemistry
- Spectroscopy
- Chemical Physics
Background:
- Halogen bonding is a significant non-covalent interaction.
- Perfluoroalkanes are widely used in various chemical applications.
- Pyridine is a common Lewis base used in chemical studies.
Purpose of the Study:
- To investigate halogen bonding interactions between specific iodo-perfluoroalkanes and pyridine.
- To quantify the strength of these interactions using spectroscopic methods.
- To compare halogen bonding with hydrogen bonding in similar systems.
Main Methods:
- Noisy light-based coherent anti-Stokes Raman scattering (I((2)) CARS) spectroscopy was employed.
- Mole fraction and temperature studies were conducted.
- The ring breathing mode of pyridine was analyzed for spectral shifts.
Main Results:
- The ring breathing mode of pyridine is sensitive to halogen bonding, showing a proportional blue-shift with interaction strength.
- The observed blue-shifts for halogen bonding were comparable to those of hydrogen bonding between pyridine and water.
- 2-Iodo-perfluoropropane exhibited distinct thermodynamic behavior compared to 1-iodo-perfluoroalkanes.
Conclusions:
- Halogen bonding interactions between iodo-perfluoroalkanes and pyridine can be effectively studied using I((2)) CARS spectroscopy.
- The strength of halogen bonding is comparable to hydrogen bonding in this system.
- A molecular-level difference in thermodynamic behavior exists between branched and linear iodo-perfluoroalkanes.
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