Related Experiment Videos
Infrared spectra of CO2-H2 complexes
1Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario. robert.mckellar@nrc.ca
The Journal of Chemical Physics
|May 25, 2005
Summary
Researchers studied carbon dioxide-hydrogen complexes using infrared spectroscopy. The CO(2)-para-H(2) complex exhibits a T-shaped structure and a redshifted vibration, unlike the more complex ortho-H(2) spectra.
Area of Science:
- Molecular Spectroscopy
- Intermolecular Forces
- Quantum Chemistry
Background:
- Weakly bound complexes provide insights into intermolecular interactions.
- Understanding molecular complexes is crucial for various fields, including atmospheric science and astrochemistry.
Purpose of the Study:
- To investigate the infrared spectra of carbon dioxide-hydrogen (CO(2)-H(2)) complexes.
- To determine the structure and vibrational properties of these complexes.
Main Methods:
- Utilized tunable diode laser probe spectroscopy.
- Employed pulsed supersonic jet expansion for complex formation.
- Analyzed spectra using an asymmetric rotor Hamiltonian.
Main Results:
- Observed and analyzed spectra for CO(2)-para-H(2) isotopic species.
- Identified a T-shaped structure for CO(2)-para-H(2) with an intermolecular distance of ~3.5 Angstroms.
- Detected a small redshift (-0.20 cm(-1)) in the CO(2) v(3) vibration within the complex.
- Observed complex, unassignable spectra for CO(2)-ortho-H(2).
Conclusions:
- The symmetry of CO(2) and spin statistics of oxygen nuclei lead to missing rotational levels in CO(2)-para-H(2) spectra.
- The behavior of CO(2)-H(2) spectra differs significantly between para-H(2) and ortho-H(2) forms, unlike related OCS-H(2) and N(2)O-H(2) systems.