[18]-Annulene
- Formula: C18H18
- Molecular weight: 234.3355
- IUPAC Standard InChI: InChI=1S/C18H18/c1-2-4-6-8-10-12-14-16-18-17-15-13-11-9-7-5-3-1/h1-18H/b2-1-,3-1+,4-2+,5-3+,6-4+,7-5-,8-6-,9-7+,10-8+,11-9+,12-10+,13-11-,14-12-,15-13+,16-14+,17-15+,18-16+,18-17-
- IUPAC Standard InChIKey: STQWAGYDANTDNA-DWSNDWDZSA-N
- CAS Registry Number: 2040-73-5
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: (1,3,5,7,9,11,13,15,17)-Cyclooctadecanonaene
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Condensed phase thermochemistry data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°solid | 39.0 ± 4.0 | kcal/mol | Ccb | Beezer, Mortimer, et al., 1965 | |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -2346.8 ± 4.0 | kcal/mol | Ccb | Beezer, Mortimer, et al., 1965 | Corresponding ΔfHºsolid = 39.0 kcal/mol (simple calculation by NIST; no Washburn corrections) |
Phase change data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔsubH° | 28. ± 2. | kcal/mol | E | Beezer, Mortimer, et al., 1965 | ALS |
| ΔsubH° | 27.96 | kcal/mol | N/A | Beezer, Mortimer, et al., 1965 | DRB |
Gas phase ion energetics data
Go To: Top, Condensed phase thermochemistry data, Phase change data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 6.60 | PE | Baumann, Bunzli, et al., 1982 | LBLHLM |
| 7.23 | PE | Baumann, Bunzli, et al., 1982 | Vertical value; LBLHLM |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Beezer, Mortimer, et al., 1965
Beezer, A.E.; Mortimer, C.T.; Springall, H.D.; Sondheimer, F.; Wolovsky, R.,
33. The heat of combustion of cyclo-octadecanonaene ([18]annulene),
J. Chem. Soc., 1965, 216-220. [all data]
Baumann, Bunzli, et al., 1982
Baumann, H.; Bunzli, J.-C.; Oth, J.F.M.,
58. The photoelectron spectrum of [18]annulene,
Helv. Chim. Acta, 1982, 65, 582. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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