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A Novel Technique for Raman Analysis of Highly Radioactive Samples Using Any Standard Micro-Raman Spectrometer
Published on: April 12, 2017
Communication: overtone (2NH) spectroscopy of NH3-Ar
K Didriche1, T Földes, T Vanfleteren
1Laboratoire de Chimie quantique et Photophysique, CP160∕09, Faculté des Sciences, Université Libre de Bruxelles, 50 ave. Roosevelt, B-1050 Brussels, Belgium. kdidrich@ulb.ac.be
The Journal of Chemical Physics
|May 17, 2013
Summary
High-resolution spectroscopy reveals the ammonia-argon (NH3-Ar) van der Waals complex. Researchers determined rotational constants and predissociation lifetimes for the NH3-Ar complex, averaging 0.6 ns.
Area of Science:
- Physical Chemistry
- Molecular Spectroscopy
- Intermolecular Forces
Background:
- Van der Waals complexes are crucial for understanding intermolecular interactions.
- Ammonia-argon (NH3-Ar) complexes provide insights into hydrogen bonding and weak interactions.
- Supersonic jet expansions are effective for creating and studying weakly bound molecular complexes.
Purpose of the Study:
- To investigate the Π (1(1)) ← Σ (0(0)) 2NH (ν1+ν3) vibrational band of the NH3-Ar complex.
- To determine the rotational constants of the excited state of the NH3-Ar complex.
- To measure the predissociation lifetimes of the NH3-Ar complex using high-resolution spectroscopy.
Main Methods:
- Cavity ring down spectroscopy (CRDS) was employed for high-resolution recording of the spectral band.
- Analysis of spectral linewidths was used to estimate J-dependent predissociation lifetimes.
- The NH3-Ar complex was formed in a supersonic jet expansion.
Main Results:
- The origin of the 2NH (ν1+ν3) band was identified at 6628 cm(-1).
- Upper state rotational constants for the NH3-Ar complex were successfully determined.
- J-dependent predissociation lifetimes were estimated, with a mean value of approximately 0.6 ns.
Conclusions:
- The study provides detailed spectroscopic characterization of the NH3-Ar van der Waals complex.
- The determined rotational constants and lifetimes offer valuable data for theoretical modeling of weak interactions.
- The findings contribute to the understanding of energy relaxation pathways in weakly bound molecular systems.
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