Ketene

Formula: C₂H₂O
Molecular weight: 42.0367
IUPAC Standard InChI: InChI=1S/C2H2O/c1-2-3/h1H2
IUPAC Standard InChIKey: CCGKOQOJPYTBIH-UHFFFAOYSA-N
CAS Registry Number: 463-51-4
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: Ethenone; Carbomethene; CH2CO; Keto-ethylene
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Gas phase thermochemistry data

Go To: Top, Phase change data, Reaction thermochemistry data, References, Notes

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-87.24	kJ/mol	Ion	Orlov, Krivoruchko, et al., 1986	Author was aware that data differs from previously reported values; ALS
Δ_fH°_gas	-48. ± 2.	kJ/mol	Cm	Nuttall, Laufer, et al., 1971	ALS
Δ_fH°_gas	-61.84	kJ/mol	Cm	Rice and Greenberg, 1934	ALS

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
33.26	50.	Thermodynamics Research Center, 1997	p=1 bar. Selected entropies and heat capacities are in excellent agreement with statistically calculated values [ Cox A.P., 1963, Moore C.B., 1963] and value of S(298.15 K) calculated by ab initio method [ East A.L.L., 1997]. Maximum discrepancies with earlier calculations [ Drayton L.G., 1948, Sundaram S., 1960] amount to 6 and 4 J/molK for S(T) and Cp(T), respectively. S(T) values calculated by [ Zhuravlev E.Z., 1959] are 11-13 J/molK lower than recommended ones.; GT
34.23	100.
37.92	150.
42.74	200.
49.59	273.15
51.75	298.15
51.91	300.
59.49	400.
65.61	500.
70.66	600.
74.94	700.
78.64	800.
81.88	900.
84.71	1000.
87.19	1100.
89.35	1200.
91.25	1300.
92.91	1400.
94.36	1500.

Phase change data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, References, Notes

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos

Quantity	Value	Units	Method	Reference	Comment
Δ_vapH°	20.4 ± 5.9	kJ/mol	V	Reuben, 1969	ALS

Enthalpy of vaporization

Δ_vapH (kJ/mol)	Temperature (K)	Method	Reference	Comment
20.4 ± 0.1	209.	A,MM	Stephenson and Malanowski, 1987	Based on data from 159. to 224. K. See also Reuben, 1969, 2.; AC

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)

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Temperature (K)	A	B	C	Reference	Comment
159.3 to 223.80	3.97722	766.685	-30.609	Reuben, 1969, 2	Coefficents calculated by NIST from author's data.

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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

(CAS Reg. No. 77213-00-4 • 4294967295 Ketene ) + Ketene = CAS Reg. No. 77213-00-4

By formula: (CAS Reg. No. 77213-00-4 • 4294967295C₂H₂O) + C₂H₂O = CAS Reg. No. 77213-00-4

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	181. ± 16.	kJ/mol	N/A	Marks, Brauman, et al., 1988	gas phase; B
Δ_rH°	187. ± 16.	kJ/mol	Ther	Farid and McMahon, 1980	gas phase; Between MeCOCH₂F, cyclopentadiene; value altered from reference due to change in acidity scale; B
Δ_rH°	186. ± 16.	kJ/mol	N/A	Wenthold and Squires, 1995	gas phase; Re-evaluation of literature thermo cycle; B
Δ_rH°	148. ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1983	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	115. ± 8.4	kJ/mol	IMRE	Larson and McMahon, 1983	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B

+ Ketene = ( • Ketene )

By formula: F^- + C₂H₂O = (F^- • C₂H₂O)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	148.	kJ/mol	ICR	Larson and McMahon, 1983	gas phase; switching reaction(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	111.	J/mol*K	N/A	Larson and McMahon, 1983	gas phase; switching reaction(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	115.	kJ/mol	ICR	Larson and McMahon, 1983	gas phase; switching reaction(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M

C₂HO^- + = Ketene

By formula: C₂HO^- + H⁺ = C₂H₂O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1526. ± 8.8	kJ/mol	G+TS	Oakes, Jones, et al., 1983	gas phase; Acid: ketene; value altered from reference due to change in acidity scale; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1497. ± 8.4	kJ/mol	IMRB	Oakes, Jones, et al., 1983	gas phase; Acid: ketene; value altered from reference due to change in acidity scale; B

(C₂H₃O^- • 4294967295 Ketene ) + Ketene = C₂H₃O^-

By formula: (C₂H₃O^- • 4294967295C₂H₂O) + C₂H₂O = C₂H₃O^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	257. ± 9.6	kJ/mol	N/A	Bartmess, Scott, et al., 1979	gas phase; Acid: ethanal. The enol is 9.6 kcal/mol more acidic: Holmes and Lossing, 1982; value altered from reference due to change in acidity scale; B

(CAS Reg. No. 78944-68-0 • 4294967295 Ketene ) + Ketene = CAS Reg. No. 78944-68-0

By formula: (CAS Reg. No. 78944-68-0 • 4294967295C₂H₂O) + C₂H₂O = CAS Reg. No. 78944-68-0

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	143. ± 4.6	kJ/mol	N/A	Nimlos, Soderquist, et al., 1989	gas phase; B
Δ_rH°	6.7 ± 9.2	kJ/mol	Ther	DePuy, Bierbaum, et al., 1985	gas phase; B

+ Ketene =

By formula: HNaO + C₂H₂O = C₂H₃NaO₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-208.2 ± 1.6	kJ/mol	Cm	Nuttall, Laufer, et al., 1971	gas phase; ALS
Δ_rH°	-197.3	kJ/mol	Cm	Rice and Greenberg, 1934	gas phase; ALS

(CAS Reg. No. 64723-96-2 • 4294967295 Ketene ) + Ketene = CAS Reg. No. 64723-96-2

By formula: (CAS Reg. No. 64723-96-2 • 4294967295C₂H₂O) + C₂H₂O = CAS Reg. No. 64723-96-2

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	203. ± 9.6	kJ/mol	N/A	Bartmess, Scott, et al., 1979	gas phase; value altered from reference due to change in acidity scale; B

(CAS Reg. No. 211040-82-3 • 4294967295 Ketene ) + Ketene = CAS Reg. No. 211040-82-3

By formula: (CAS Reg. No. 211040-82-3 • 4294967295C₂H₂O) + C₂H₂O = CAS Reg. No. 211040-82-3

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	122. ± 12.	kJ/mol	N/A	Taft, 1987	gas phase; value altered from reference due to change in acidity scale; B

= Ketene +

By formula: C₄H₆O₂S = C₂H₂O + C₂H₄OS

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	94.7	kJ/mol	Eqk	Blake and Speis, 1974	gas phase; Heat of formation derived by 77PED/RYL; ALS

(CAS Reg. No. 84148-57-2 • 4294967295 Ketene ) + Ketene = CAS Reg. No. 84148-57-2

By formula: (CAS Reg. No. 84148-57-2 • 4294967295C₂H₂O) + C₂H₂O = CAS Reg. No. 84148-57-2

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	231. ± 13.	kJ/mol	N/A	Grabowski and Cheng, 1989	gas phase; B

Ketene + =

By formula: C₂H₂O + C₂H₄O₂ = C₄H₆O₃

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-87.5 ± 2.2	kJ/mol	Eqk	Blake, Davies, et al., 1971	gas phase; ALS

Ketene + =

By formula: C₂H₂O + C₄H₁₀O = C₆H₁₂O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-146.9	kJ/mol	Cm	Rice and Greenberg, 1934	liquid phase; ALS

Ketene + =

By formula: C₂H₂O + C₄H₁₀O = C₆H₁₂O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-143.8	kJ/mol	Cm	Rice and Greenberg, 1934	liquid phase; ALS

Ketene + =

By formula: C₂H₂O + C₄H₁₀O = C₆H₁₂O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-144.5	kJ/mol	Cm	Rice and Greenberg, 1934	liquid phase; ALS

Ketene + =

By formula: C₂H₂O + C₄H₁₀O = C₆H₁₂O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-98.28	kJ/mol	Cm	Rice and Greenberg, 1934	liquid phase; ALS

Ketene + =

By formula: C₂H₂O + C₃H₈O = C₅H₁₀O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-150.2	kJ/mol	Cm	Rice and Greenberg, 1934	liquid phase; ALS

Ketene + =

By formula: C₂H₂O + C₂H₄OS = C₄H₆O₂S

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-94.7	kJ/mol	Eqk	Blake and Speis, 1974	gas phase; ALS

Ketene + =

By formula: C₂H₂O + C₂H₆O = C₄H₈O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-152.5	kJ/mol	Cm	Rice and Greenberg, 1934	gas phase; ALS

Ketene + =

By formula: C₂H₂O + C₃H₈O = C₅H₁₀O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-147.8	kJ/mol	Cm	Rice and Greenberg, 1934	gas phase; ALS

Ketene + =

By formula: C₂H₂O + CH₄O = C₃H₆O₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-154.5	kJ/mol	Cm	Rice and Greenberg, 1934	gas phase; ALS

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Notes

Orlov, Krivoruchko, et al., 1986
Orlov, V.M.; Krivoruchko, A.A.; Misharev, A.D.; Takhistov, V.V., Enthalpy of vapor phase formation of ketene, ethynol, and their analogs, Bull. Acad. Sci. USSR, Div. Chem. Sci., 1986, 2404-2405. [all data]

Nuttall, Laufer, et al., 1971
Nuttall, R.L.; Laufer, A.H.; Kilday, M.V., The enthalpy of formation of ketene, J. Chem. Thermodyn., 1971, 3, 167-174. [all data]

Rice and Greenberg, 1934
Rice, F.O.; Greenberg, J., Ketene. III. Heat of formation and heat of reaction with alcohols, J. Am. Chem. Soc., 1934, 38, 2268-2270. [all data]

Thermodynamics Research Center, 1997
Thermodynamics Research Center, Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]

Cox A.P., 1963
Cox A.P., Fundamental vibrational frequencies in ketene and the deuteroketenes, J. Chem. Phys., 1963, 38, 1636-1643. [all data]

Moore C.B., 1963
Moore C.B., Infrared spectrum and vibrational potential function of ketene and the deuterated ketenes, J. Chem. Phys., 1963, 38, 2816-2829. [all data]

East A.L.L., 1997
East A.L.L., Ab initio statistical thermodynamical models for the computation of third-law entropies, J. Chem. Phys., 1997, 106, 6655-6674. [all data]

Drayton L.G., 1948
Drayton L.G., The infrared spectrum of ketene, J. Chem. Soc., 1948, 1416-1419. [all data]

Sundaram S., 1960
Sundaram S., Potential energy constants, rotational distortion constants, and thermodynamic properties of H2C=C=O and D2C=C=O, J. Chem. Phys., 1960, 32, 1554-1556. [all data]

Zhuravlev E.Z., 1959
Zhuravlev E.Z., Isotopic effect on thermodynamic functions of some organic deuterocompounds in the ideal gas state, Tr. Khim. i Khim. Tekhnol., 1959, 2, 475-485. [all data]

Reuben, 1969
Reuben, B.G., Vapor pressure of ketene, J. Chem. Eng. Data, 1969, 14, 235. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Reuben, 1969, 2
Reuben, Bryan G., Vapor pressure of ketene, J. Chem. Eng. Data, 1969, 14, 2, 235-236, https://doi.org/10.1021/je60041a008 . [all data]

Marks, Brauman, et al., 1988
Marks, J.; Brauman, J.I.; Mead, R.D.; Lykke, K.R.; Lineberger, W.C., Spectroscopy and Dynamics of the Dipole Supported State of Acetyl Fluoride Enolate Anion, J. Chem. Phys., 1988, 88, 11, 6785, https://doi.org/10.1063/1.454424 . [all data]

Farid and McMahon, 1980
Farid, R.; McMahon, T.B., The gas phase acidities of fluorinated acetones. An ICR investigation of the role of fluorine substituents in the stabilization of planar carbanions, Can. J. Chem., 1980, 58, 2307. [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R., Bond dissociation energies of F2(-) and HF2(-). A gas-phase experimental and G2 theoretical study, J. Phys. Chem., 1995, 99, 7, 2002, https://doi.org/10.1021/j100007a034 . [all data]

Larson and McMahon, 1983
Larson, J.W.; McMahon, T.B., Strong hydrogen bonding in gas-phase anions. An ion cyclotron resonance determination of fluoride binding energetics to bronsted acids from gas-phase fluoride exchange equilibria measurements, J. Am. Chem. Soc., 1983, 105, 2944. [all data]

Arshadi, Yamdagni, et al., 1970
Arshadi, M.; Yamdagni, R.; Kebarle, P., Hydration of Halide Negative Ions in the Gas Phase. II. Comparison of Hydration Energies for the Alkali Positive and Halide Negative Ions, J. Phys. Chem., 1970, 74, 7, 1475, https://doi.org/10.1021/j100702a014 . [all data]

Oakes, Jones, et al., 1983
Oakes, J.M.; Jones, M.E.; Bierbaum, V.M.; Ellison, G.B., Photoelectron spectroscopy of CCO^- and HCCO^-, J. Phys. Chem., 1983, 87, 4810. [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Holmes and Lossing, 1982
Holmes, J.L.; Lossing, F.P., Heats of formation of the ionic and neutral enols of acetaldehyde and acetone, J. Am. Chem. Soc., 1982, 104, 2648. [all data]

Nimlos, Soderquist, et al., 1989
Nimlos, M.R.; Soderquist, J.A.; Ellison, G.B., Spectroscopy of CH3CO- and CH3CO, J. Am. Chem. Soc., 1989, 111, 20, 7675, https://doi.org/10.1021/ja00202a001 . [all data]

DePuy, Bierbaum, et al., 1985
DePuy, C.H.; Bierbaum, V.M.; Damrauer, R.; Soderquist, J.A., Gas-phase reactions of the acetyl anion, J. Am. Chem. Soc., 1985, 107, 3385. [all data]

Taft, 1987
Taft, R.W., The Nature and Analysis of Substitutent Electronic Effects, Personal communication. See also Prog. Phys. Org. Chem., 1987, 16, 1. [all data]

Blake and Speis, 1974
Blake, P.G.; Speis, A., Reactions of keten. Part IV. Kinetics and thermodynamics of the gas-phase reaction: Thioacetic acid + keten = acetic Thioanhydride, J. Chem. Soc. Perkin Trans. 2, 1974, 1879-1881. [all data]

Grabowski and Cheng, 1989
Grabowski, J.J.; Cheng, X., Gas-Phase Formation of the Enolate Monoanion of Acetic Acid by Proton Abstraction, J. Am. Chem. Soc., 1989, 111, 8, 3106, https://doi.org/10.1021/ja00190a078 . [all data]

Blake, Davies, et al., 1971
Blake, P.G.; Davies, H.H.; Speis, A., Reactions of keten. Part II. The thermodynamics of the gas-phase equilibrium: acetic acid + keten = acetic anhydride, J. Chem. Soc. B, 1971, 2050-2052. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, References

Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions
Δ_vapH	Enthalpy of vaporization
Δ_vapH°	Enthalpy of vaporization at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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