1,3,5,7-Cyclooctatetraene

Formula: C₈H₈
Molecular weight: 104.1491
IUPAC Standard InChI: InChI=1S/C8H8/c1-2-4-6-8-7-5-3-1/h1-8H/b2-1-,3-1-,4-2-,5-3-,6-4-,7-5-,8-6-,8-7-
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
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Other names: [8]Annulene; Cyclooctatetraene; UN 2358
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	71.13 ± 0.31	kcal/mol	N/A	Prosen, Johnson, et al., 1950	Value computed using Δ_fH_liquid° value of 254.5±1.3 kj/mol from Prosen, Johnson, et al., 1950 and Δ_vapH° value of 43.1±0.31 kj/mol from missing citation.; DRB
Quantity	Value	Units	Method	Reference	Comment
S°_gas	78.10 ± 0.35	cal/mol*K	N/A	Scott D.W., 1949	GT

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
8.564	50.	Dorofeeva O.V., 1986	Selected values of Cp(T) are in close agreement with those calculated by [ Lippincott E.R., 1951], while the S(T) values are 1.5-2.0 J/mol*K larger than obtained by [ Lippincott E.R., 1951].; GT
12.11	100.
15.90	150.
20.03	200.
26.883	273.15
29.30 ± 0.84	298.15
29.484	300.
38.678	400.
46.465	500.
52.811	600.
57.995	700.
62.292	800.
65.894	900.
68.939	1000.
71.532	1100.
73.745	1200.
75.645	1300.
77.280	1400.
78.695	1500.

Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	60.82 ± 0.32	kcal/mol	Cm	Prosen, Johnson, et al., 1950	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-1084.9 ± 0.7	kcal/mol	Ccb	Springall, White, et al., 1954	Corresponding Δ_fHº_liquid = 59.2 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-1086.50 ± 0.22	kcal/mol	Cm	Prosen, Johnson, et al., 1950	Corresponding Δ_fHº_liquid = 60.83 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	52.651	cal/mol*K	N/A	Scott, Gross, et al., 1949	DH

Constant pressure heat capacity of liquid

C_p,liquid (cal/mol*K)	Temperature (K)	Reference	Comment
44.259	298.15	Scott, Gross, et al., 1949	T = 12 to 340 K.; DH

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Notes

Prosen, Johnson, et al., 1950
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 of styrene, J. Am. Chem. Soc., 1950, 72, 626-629. [all data]

Scott D.W., 1949
Scott D.W., Cyclooctatetraene: low-temperature heat capacity, heat of fusion, heat of vaporization, vapor pressure, and entropy, J. Am. Chem. Soc., 1949, 71, 1634-1636. [all data]

Dorofeeva O.V., 1986
Dorofeeva O.V., Thermodynamic properties of twenty-one monocyclic hydrocarbons, J. Phys. Chem. Ref. Data, 1986, 15, 437-464. [all data]

Lippincott E.R., 1951
Lippincott E.R., The thermodynamic functions of cyclooctatetraene, J. Am. Chem. Soc., 1951, 73, 3889-3891. [all data]

Springall, White, et al., 1954
Springall, H.D.; White, T.R.; Cass, R.C., Heats of combustion and molecular structure Part 1.- The resonance energy and structure of cyclo-octateraene, Trans. Faraday Soc., 1954, 50, 815. [all data]

Scott, Gross, et al., 1949
Scott, D.W.; Gross, M.E.; Oliver, G.D.; Huffman, H.M., Cycloöctatetraene: low-temperature heat capacity, heat of fusion, heat of vaporization, vapor pressure and entropy, J. Am. Chem. Soc., 1949, 71, 1634-1636. [all data]

Notes

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Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
S°_gas	Entropy of gas at standard conditions
S°_liquid	Entropy of liquid at standard conditions
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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