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Hydrogen-Bonding Modification in Biuret Under Pressure
Gustav M Borstad1, Jennifer A Ciezak-Jenkins1
1RDRL-WML-B, U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland 21005, United States.
The Journal of Physical Chemistry. A
|January 7, 2017
Summary
High pressure compresses biuret (C2H5N3O2), causing molecular reorientation and reversible structural changes. Raman spectroscopy and X-ray diffraction reveal these pressure-induced effects on molecular vibrations and crystal structure.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Spectroscopy
Background:
- Biuret (C2H5N3O2) is an organic compound with potential applications in various chemical processes.
- Understanding its behavior under extreme conditions is crucial for predicting its stability and reactivity.
Purpose of the Study:
- To investigate the structural and molecular changes in biuret under high pressure.
- To determine the pressure-induced phase transitions and reversibility of these changes.
Main Methods:
- High-pressure studies utilizing Raman spectroscopy up to 30 GPa.
- High-pressure studies utilizing X-ray diffraction up to 50 GPa.
Main Results:
- Raman spectroscopy revealed molecular reorientation in biuret at specific pressure ranges (3-5 GPa, 8-12 GPa, 16-20 GPa).
- Changes in Raman modes were linked to vibrations of N-H and C═O bonds, indicating coupling with the hydrogen-bonded lattice.
- X-ray diffraction confirmed a stable monoclinic crystal structure up to 50 GPa.
- Observed pressure-induced changes were found to be reversible, despite some hysteresis.
Conclusions:
- Biuret exhibits significant molecular reorientation and reversible structural changes under high pressure.
- The hydrogen-bonded lattice plays a critical role in the pressure response of biuret molecules.
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