Journal
MICROSCOPY
Volume 63, Issue 5, Pages 377-382Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jmicro/dfu023
Keywords
EELS; molecular vibration; liquid; low loss; ionic liquid; first-principles calculation
Categories
Funding
- Ministry of Education, Culture, Sports, Science and Technology in Japan (MEXT) [25106003, 26249092, 24350038]
- Institute of Industrial Science, University of Tokyo [5504850103]
- Grants-in-Aid for Scientific Research [13J10236, 25106003] Funding Source: KAKEN
Ask authors/readers for more resources
Investigations on the dynamic behavior of molecules in liquids at high spatial resolution are greatly desired because localized regions, such as solid-liquid interfaces or sites of reacting molecules, have assumed increasing importance with respect to improving material performance. In application to liquids, electron energy loss spectroscopy (EELS) observed with transmission electron microscopy (TEM) is a promising analytical technique with the appropriate resolutions. In this study, we obtained EELS spectra from an ionic liquid, 1-ethyl-3-methylimidazolium bis (trifluoromethyl-sulfonyl) imide (C(2)mim-TFSI), chosen as the sampled liquid, using monochromated scanning TEM (STEM). The molecular vibrational spectrum and the highest occupied molecular orbital (HOMO)lowest unoccupied molecular orbital (LUMO) gap of the liquid were investigated. The HOMO-LUMO gapmeasurement coincided with that obtained from the ultraviolet-visible spectrum. A shoulder in the spectrum observed similar to 0.4 eV is believed to originate from the molecular vibration. From a separately performed infrared observation and first-principles calculations, we found that this shoulder coincided with the vibrational peak attributed to the C-H stretching vibration of the [C(2)mim(+)] cation. This study demonstrates that a vibrational peak for a liquid can be observed using monochromated STEM-EELS, and leads one to expect observations of chemical reactions or aids in the analysis of the dynamic behavior of molecules in liquid.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available