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Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization
Published on: November 27, 2015
Hydrogen bonds and conformations in ethylene glycol under pressure
Chitra Murli1, Ning Lu, Zhaohui Dong
1Department of Chemistry, University of Western Ontario, London, Ontario, N6A5B7, Canada. cmurli@barc.gov.in
The Journal of Physical Chemistry. B
|September 19, 2012
Summary
Ethylene glycol (EG) remains a liquid with mixed conformations up to 3.1 GPa. Above 5 GPa, high-pressure Raman and infrared spectroscopy reveal a liquid-solid transition and stabilization to the gauche conformation.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Materials Science
Background:
- Ethylene glycol (EG) serves as a model for complex hydrogen bonding in biological molecules like polysaccharides and sugars.
- Understanding molecular behavior under extreme conditions is crucial for various scientific disciplines.
Purpose of the Study:
- To investigate pressure-induced conformational changes and hydrogen bonding in ethylene glycol up to 10 GPa.
- To characterize the liquid-solid transition and high-pressure phases of ethylene glycol.
Main Methods:
- In situ high-pressure Raman spectroscopy.
- In situ high-pressure infrared absorption spectroscopy.
- Visual observation of phase transitions.
Main Results:
- Ethylene glycol (EG) maintains a liquid state with a mix of trans and gauche conformations up to 3.1 GPa.
- A liquid-solid transition occurs around 4 GPa, indicated by new Raman modes and visual changes.
- New hydrogen bonding networks form before the transition, and the high-pressure phase stabilizes to the gauche conformation above 5 GPa.
Conclusions:
- High pressure significantly alters ethylene glycol's structure and hydrogen bonding.
- The gauche conformation is favored in the high-pressure solid phase of ethylene glycol.
- Spectroscopic techniques effectively probe molecular behavior under extreme pressure conditions.
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