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Redetermination of octahydrochrysene
C J Burd1, A J Dobson, R E Gerkin
1Department of Chemistry, Ohio State University, Columbus 43210, USA.
Summary
The central rings of 1,2,3,4,7,8,9,10-octahydrochrysene are planar, while the outer rings are non-planar, correcting earlier findings. This study provides precise structural data for this polycyclic aromatic hydrocarbon.
Area of Science:
- Organic Chemistry
- Crystallography
- Molecular Structure
Background:
- 1,2,3,4,7,8,9,10-octahydrochrysene (C18H20) is a polycyclic aromatic hydrocarbon.
- Previous studies suggested a different molecular geometry for its outer rings.
Purpose of the Study:
- To accurately determine the three-dimensional structure of 1,2,3,4,7,8,9,10-octahydrochrysene.
- To resolve discrepancies with prior structural analyses.
Main Methods:
- Single-crystal X-ray diffraction analysis.
- Analysis of atomic deviations from best-fit planes.
- Measurement of carbon-carbon single-bond distances.
Main Results:
- The central rings of C18H20 exhibit planarity (r.m.s. deviation of 0.013 Å).
- The outer rings are substantially non-planar, contradicting earlier photographic data.
- Carbon-carbon bond distances in the outer rings are highly uniform (range of 0.017 Å).
- No significant intermolecular contacts were observed.
Conclusions:
- The precise molecular geometry of 1,2,3,4,7,8,9,10-octahydrochrysene has been established.
- This study corrects previous structural interpretations of the molecule's outer ring conformation.
- The findings contribute to a better understanding of polycyclic aromatic hydrocarbon structures.