Pressure-induced phase transitions in MBANP crystal: A study by synchrotron radiation X-ray diffraction and Raman
M N G Ferreira Junior1, W Paraguassu2, A O Dos Santos3
1Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CEP 60740-000, Belém-PA, Brazil; Instituto Federal de Educação Ciência e Tecnologia do Pará, CEP 67125-000 Ananindeua - PA, Brazil.
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
|February 12, 2022
Summary
High pressure induces a conformational phase transition in 2-(-α-methylbenzylamino)-5-dinitropyridine (MBANP) around 0.5 GPa, confirmed by Raman spectroscopy and X-ray diffraction. This transition involves molecular changes, including benzene ring rotation.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Spectroscopy
Background:
- 2-(-α-methylbenzylamino)-5-dinitropyridine (MBANP) is a molecule of interest for its potential structural properties under external stimuli.
- Understanding molecular behavior under high pressure is crucial for developing new materials and predicting their stability.
Purpose of the Study:
- To investigate the effects of high pressure on the molecular structure and phase behavior of MBANP.
- To identify the pressure-induced phase transition and characterize the associated structural changes.
Main Methods:
- Raman spectroscopy was employed to monitor changes in molecular vibrations with increasing pressure.
- Synchrotron radiation X-ray diffraction was used to confirm structural modifications and phase transitions.
- Pressure-dependent spectral analysis and diffraction pattern interpretation were performed.
Main Results:
- Raman spectra showed significant changes with pressure, including band splitting and disappearance, indicating structural alterations.
- A conformational phase transition was observed around 0.5 GPa, evidenced by discontinuous shifts in wavenumber versus pressure plots.
- X-ray diffraction confirmed the conformational changes around 0.5 GPa, correlating with Raman observations.
- Pressure was found to induce a rotational movement of the benzene ring, linked to the observed phase transition.
Conclusions:
- MBANP undergoes a pressure-induced conformational phase transition at approximately 0.5 GPa.
- The transition is characterized by molecular rearrangements, including benzene ring rotation, as confirmed by combined spectroscopic and diffraction techniques.
- These findings provide insights into the high-pressure behavior of MBANP and related molecular systems.
