1,3,5,7-Cyclooctatetraene
- Formula: C8H8
- Molecular weight: 104.1491
- IUPAC Standard InChIKey: KDUIUFJBNGTBMD-BONZMOEMSA-N
- CAS Registry Number: 629-20-9
- 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: [8]Annulene; Cyclooctatetraene; UN 2358
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Reaction thermochemistry data
Go To: Top, Gas phase ion energetics 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:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
C8H7- + =
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 382.7 ± 2.8 | kcal/mol | G+TS | Kato, Lee, et al., 1997 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 374.8 ± 2.5 | kcal/mol | IMRE | Kato, Lee, et al., 1997 | gas phase; B |
By formula: 4H2 + C8H8 = C8H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -97.96 ± 0.05 | kcal/mol | Chyd | Turner, Meador, et al., 1957 | liquid phase; solvent: Acetic acid; ALS |
By formula: C8H8 = C8H8
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -34.35 ± 0.34 | kcal/mol | Ciso | Prosen, Johnson, et al., 1947 | liquid phase; ALS |
By formula: C8H8 = c8H8
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 5.5 ± 0.6 | kcal/mol | Eqk | Squillacote and Bergman, 1986 | gas phase; ALS |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry 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:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
View reactions leading to C8H8+ (ion structure unspecified)
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
0.570 ± 0.030 | N/A | Miller, Viggiano, et al., 2002 | B |
0.550 ± 0.020 | IMRE | Kato, Lee, et al., 1997 | B |
0.650 ± 0.043 | LPES | Wenthold, Hrovat, et al., 1996 | EA(D4h COT) = 1.099 ± 0.01 eV. D4H is TS, 10-11 kcal/mol above GS D8h; B |
0.58 ± 0.10 | CIDC | Denault, Chen, et al., 1998 | entropy of attachment: -14.7±13 eu; B |
<0.823919 | PD | Gygax, Peters, et al., 1979 | B |
0.577 ± 0.043 | ECD | Wentworth and Ristau, 1969 | B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.03 | PE | Fu and Dunbar, 1978 | LLK |
8.0 | PE | Batich, Bischof, et al., 1973 | LLK |
8.21 | PE | Dewar, Harget, et al., 1969 | Unpublished result of M.J.S. Dewar and S.D. Worley; RDSH |
8.04 | PE | Al-Joboury and Turner, 1964 | RDSH |
7.99 ± 0.02 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
8.43 | PE | Fu and Dunbar, 1978 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C3H3+ | 13.40 ± 0.10 | ? | EI | Franklin and Carroll, 1969 | RDSH |
C4H2+ | 17.11 ± 0.10 | 2C2H2+H2 | EI | Franklin and Carroll, 1969 | RDSH |
C4H3+ | 18.16 ± 0.25 | 2C2H2+H | EI | Franklin and Carroll, 1969 | RDSH |
C4H4+ | 15.10 ± 0.10 | 2C2H2 | EI | Franklin and Carroll, 1969 | RDSH |
C5H3+ | 16.41 ± 0.15 | C2H2+CH3? | EI | Franklin and Carroll, 1969 | RDSH |
C6H5+ | 14.58 ± 0.10 | C2H2+H | EI | Franklin and Carroll, 1969 | RDSH |
C6H6+ | 9.4 ± 0.05 | C2H2 | TRPI | Lifshitz and Malinovich, 1984 | LBLHLM |
C6H6+ | 9.70 ± 0.12 | C2H2 | EI | Franklin and Carroll, 1969 | RDSH |
C8H6+ | 11.70 ± 0.10 | H2 | EI | Franklin and Carroll, 1969 | RDSH |
C8H7+ | 10.90 ± 0.10 | H | EI | Franklin and Carroll, 1969 | RDSH |
De-protonation reactions
C8H7- + =
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 382.7 ± 2.8 | kcal/mol | G+TS | Kato, Lee, et al., 1997 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 374.8 ± 2.5 | kcal/mol | IMRE | Kato, Lee, et al., 1997 | gas phase; B |
References
Go To: Top, Reaction thermochemistry 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.
Kato, Lee, et al., 1997
Kato, S.; Lee, H.S.; Gareyev, R.; Wenthold, P.G.; Lineberger, W.C.; DePuy, C.H.; Bierbaum, V.M.,
Experimental and Computational Studies of the Structures and Energetics of Cyclooctatetraene and Its Derivatives,
J. Am. Chem. Soc., 1997, 119, 33, 7863, https://doi.org/10.1021/ja971433d
. [all data]
Turner, Meador, et al., 1957
Turner, R.B.; Meador, W.R.; Doering, W.E.; Knox, L.H.; Mayer, J.R.; Wiley, D.W.,
Heats of hydrogenation. III. Hydrogenation of cycllooctatetraene and of some seven-membered non-benzenoid aromatic compounds,
J. Am. Chem. Soc., 1957, 79, 4127-4133. [all data]
Prosen, Johnson, et al., 1947
Prosen, E.J.; Johnson, W.H.; Rossini, F.D.,
Heat of combustion and formation of 1,3,5,7-cyclooctatetraene and its heat of isomerization to styrene,
J. Am. Chem. Soc., 1947, 69, 2068-2069. [all data]
Squillacote and Bergman, 1986
Squillacote, M.E.; Bergman, A.,
Trapping of 1,3,5,7-cyclooctatetraene valence tautomers. Thermodynamic stability of bicyclo[4.2.0]octa-2,4,7-triene,
J. Org. Chem., 1986, 51, 3910-3911. [all data]
Miller, Viggiano, et al., 2002
Miller, T.M.; Viggiano, A.A.; Miller, A.E.S.,
Electron attachment and detachment: Cyclooctatetraene,
J. Phys. Chem. A, 2002, 106, 43, 10200-10204, https://doi.org/10.1021/jp0205214
. [all data]
Wenthold, Hrovat, et al., 1996
Wenthold, P.G.; Hrovat, D.A.; Borden, W.T.; Lineberger, W.C.,
Transition State Spectroscopy of Cyclooctatetraene,
Science, 1996, 272, 5267, 1456, https://doi.org/10.1126/science.272.5267.1456
. [all data]
Denault, Chen, et al., 1998
Denault, J.W.; Chen, G.D.; Cooks, R.G.,
Electron affinity of 1,3,5,7-cyclooctatetraene determined by the kinetic method,
J. Am. Soc. Mass Spectrom., 1998, 9, 11, 1141-1145, https://doi.org/10.1016/S1044-0305(98)00092-0
. [all data]
Gygax, Peters, et al., 1979
Gygax, R.; Peters, H.L.; Brauman, J.I.,
Photodetachment of electrons from anions of high symmetry. Electron photodetachment spectra of the cycloctatetraenyl and perinaphthenyl anions,
J. Am. Chem. Soc., 1979, 101, 2567. [all data]
Wentworth and Ristau, 1969
Wentworth, W.E.; Ristau, W.,
Thermal Electron Attachment Involving a Change in Molecular Geometry,
J. Phys. Chem., 1969, 73, 7, 2126, https://doi.org/10.1021/j100727a005
. [all data]
Fu and Dunbar, 1978
Fu, E.W.; Dunbar, R.C.,
Photodissociation spectroscopy and structural rearrangements in ions of cyclooctatetraene, styrene and related molecules,
J. Am. Chem. Soc., 1978, 100, 2283. [all data]
Batich, Bischof, et al., 1973
Batich, C.; Bischof, P.; Heilbronner, E.,
The photoelectron spectra of cyclooctatetraene and its hydrogenated derivatives,
J. Electron Spectrosc. Relat. Phenom., 1973, 1, 333. [all data]
Dewar, Harget, et al., 1969
Dewar, M.J.S.; Harget, A.; Haselbach, E.,
Cyclooctatetraene and ions derived from it,
J. Am. Chem. Soc., 1969, 91, 7521. [all data]
Al-Joboury and Turner, 1964
Al-Joboury, M.I.; Turner, D.W.,
Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials,
J. Chem. Soc., 1964, 4434. [all data]
Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J.,
Ionization potentials of some molecules,
J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]
Franklin and Carroll, 1969
Franklin, J.L.; Carroll, S.R.,
The effect of molecular structure on ionic decomposition. I. An electron impact study of seven C8H8 isomers,
J. Am. Chem. Soc., 1969, 91, 5940. [all data]
Lifshitz and Malinovich, 1984
Lifshitz, C.; Malinovich, Y.,
Time resolved photoionization mass spectrometry in the millisecond range,
Int. J. Mass Spectrom. Ion Processes, 1984, 60, 99. [all data]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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