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Updated: Jun 24, 2026
09:38
Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
The C7 cluster: structure and infrared frequencies.
J R Heath1, R A Sheeks, A L Cooksy
1Department of Chemistry, University of California, Berkeley 94720, USA.
Science (New York, N.Y.)
|August 24, 1990
Summary
Researchers observed and characterized the C7 carbon cluster, determining its linear structure and vibrational properties. This finding aids in the potential astrophysical detection of this carbon cluster.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Astrochemistry
Background:
- Carbon clusters are crucial in interstellar chemistry and material science.
- Understanding the properties of small carbon clusters like C7 is essential for astrophysical modeling.
- Previous characterization of C7 has been limited, necessitating further investigation.
Purpose of the Study:
- To observe and characterize the C7 carbon cluster.
- To determine the molecular structure and vibrational frequencies of C7.
- To provide data facilitating the astrophysical detection of C7.
Main Methods:
- Laser vaporization of graphite to produce carbon clusters.
- Supersonic expansion in an argon jet for cluster formation.
- Diode laser absorption spectroscopy with gated detection to probe rovibrational lines.
Main Results:
- Observed 36 rovibrational lines of the nu 4 antisymmetric stretch fundamental of C7.
- Spectrum confirmed C7 as a symmetrical linear molecule.
- Determined an effective average bond length of 1.2736(4) angstroms.
- Measured a vibrational frequency of 2138.1951(10) reciprocal centimeters.
Conclusions:
- The experimental results for C7 align well with ab initio calculations.
- The characterization provides key spectroscopic data for C7.
- This study enhances the prospects for identifying C7 in astrophysical environments.
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