Acetylacetone
- Formula: C5H8O2
- Molecular weight: 100.1158
- IUPAC Standard InChIKey: YRKCREAYFQTBPV-UHFFFAOYSA-N
- CAS Registry Number: 123-54-6
- 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: 2,4-Pentanedione; Acetoacetone; Diacetylmethane; Pentane-2,4-dione; 2-Propanone, acetyl-; 2,4-Dioxopentane; 2,4-Pentadione; CH3COCH2COCH3; Acetone, acetyl-; ACAC; Pentanedione; Pentanedione-2,4; Acetyl 2-propanone; UN 2310; 2,4-Pentandione; Pentan-2,4-dione; NSC 5575
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Phase change data
Go To: Top, Gas phase ion energetics data, Ion clustering 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
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 |
---|---|---|---|---|---|
Tboil | 411. ± 2. | K | AVG | N/A | Average of 9 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 249.95 | K | N/A | Timmermans, 1921 | Uncertainty assigned by TRC = 0.3 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 254.8 | K | N/A | Melia and Merrifield, 1969 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 9.986 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 10.3 ± 0.02 | kcal/mol | V | Hacking and Pilcher, 1979 | Heat of enolization=-11.3±0.4 kJ/mol; ALS |
ΔvapH° | 10.3 ± 0.24 | kcal/mol | C | Irving and Wads, 1970 | ALS |
Reduced pressure boiling point
Tboil (K) | Pressure (atm) | Reference | Comment |
---|---|---|---|
412.2 | 0.982 | Weast and Grasselli, 1989 | BS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
9.42 | 347. | N/A | Melia and Merrifield, 2007 | Based on data from 297. to 398. K.; AC |
8.41 | 393. | A,I,EB | Stephenson and Malanowski, 1987 | Based on data from 378. to 411. K. See also Nakanishi and Toyama, 1972.; AC |
10.2 | 303. | A,EB | Stephenson and Malanowski, 1987 | Based on data from 288. to 378. K.; AC |
8.20 | 411.1 | N/A | Majer and Svoboda, 1985 | |
9.37 | 322. | EB | Raviprasad and Venkateswara Rao, 1985 | Based on data from 307. to 414. K.; AC |
9.70 | 304. | N/A | Inoue, Arai, et al., 1981 | Based on data from 295. to 313. K.; AC |
Gas phase ion energetics data
Go To: Top, Phase change data, Ion clustering data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 8.85 ± 0.02 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 208.8 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 200.0 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.85 ± 0.05 | PE | Houk, Davis, et al., 1973 | LLK |
8.82 ± 0.02 | PI | Shigorin, Filyugina, et al., 1967 | RDSH |
8.87 ± 0.03 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
9.63 ± 0.01 | PE | Hush, Livett, et al., 1987 | Vertical value; LBLHLM |
9.15 | PE | Cauletti, Furlani, et al., 1980 | Vertical value; LLK |
9.00 | PE | Schweig, Vermeer, et al., 1974 | Vertical value; LLK |
9.18 ± 0.07 | PE | Evans, Hamnett, et al., 1972 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C4H5O2+ | 10.7 ± 0.1 | CH3 | EI | Reichert and Westmore, 1969 | RDSH |
C4H5O2+ | 10.24 | CH3 | PI | Shigorin, Filyugina, et al., 1967 | RDSH |
De-protonation reactions
C5H7O2- + =
By formula: C5H7O2- + H+ = C5H8O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 343.8 ± 2.1 | kcal/mol | G+TS | Taft and Bordwell, 1988 | gas phase; at 330K: neutral enol/keto ratio should be 8:1 ( Strohmeier and Höhne, 1952); B |
ΔrH° | 343.7 ± 2.3 | kcal/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; At 500K: neutral enol/keto ratio is 1.7:1, Folkendt, Weiss-Lopez, et al., 1989. ΔH=-4.7 kcal/mol, enol favored. Carbonyls anti in anion, via calc: Irikura, 1999; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 336.7 ± 2.0 | kcal/mol | IMRE | Taft and Bordwell, 1988 | gas phase; at 330K: neutral enol/keto ratio should be 8:1 ( Strohmeier and Höhne, 1952); B |
ΔrG° | 336.6 ± 2.0 | kcal/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; At 500K: neutral enol/keto ratio is 1.7:1, Folkendt, Weiss-Lopez, et al., 1989. ΔH=-4.7 kcal/mol, enol favored. Carbonyls anti in anion, via calc: Irikura, 1999; B |
Ion clustering data
Go To: Top, Phase change data, 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
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: Cl- + C5H8O2 = (Cl- • C5H8O2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrG° | 13.40 | kcal/mol | TDEq | French, Ikuta, et al., 1982 | gas phase; B |
Free energy of reaction
ΔrG° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
11.0 | 421. | PHPMS | French, Ikuta, et al., 1982 | gas phase; M |
By formula: I- + C5H8O2 = (I- • C5H8O2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 15.1 ± 1.0 | kcal/mol | TDAs | Caldwell, Masucci, et al., 1989 | gas phase; B,M |
References
Go To: Top, Phase change data, Gas phase ion energetics data, Ion clustering data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Timmermans, 1921
Timmermans, J.,
The Freezing Points of Organic Substances IV. New Exp. Determinations,
Bull. Soc. Chim. Belg., 1921, 30, 62. [all data]
Melia and Merrifield, 1969
Melia, T.P.; Merrifield, R.,
Thermal properties of acetylacetone,
J. Appl. Chem., 1969, 19, 79-82. [all data]
Majer and Svoboda, 1985
Majer, V.; Svoboda, V.,
Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]
Hacking and Pilcher, 1979
Hacking, J.M.; Pilcher, G.,
Enthalpy of combustion of pentane-2,4-dione,
J. Chem. Thermodyn., 1979, 11, 1015-1017. [all data]
Irving and Wads, 1970
Irving, R.J.; Wads, I.,
Enthalpy of vaporization of organic compounds at 25°C. V. Acetylacetone,
Acta Chem. Scand., 1970, 24, 589-592. [all data]
Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]
Melia and Merrifield, 2007
Melia, T.P.; Merrifield, R.,
Thermal properties of acetylacetone,
J. Appl. Chem., 2007, 19, 3, 79-82, https://doi.org/10.1002/jctb.5010190305
. [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]
Nakanishi and Toyama, 1972
Nakanishi, Koichiro; Toyama, Osamu,
Vapor Pressure of Acetylacetone below Normal Boiling Point,
Bull. Chem. Soc. Jpn., 1972, 45, 10, 3210-3211, https://doi.org/10.1246/bcsj.45.3210
. [all data]
Raviprasad and Venkateswara Rao, 1985
Raviprasad, A.; Venkateswara Rao, K.,
Vapour pressure of 2,4-pentanedione,
The Journal of Chemical Thermodynamics, 1985, 17, 2, 117-121, https://doi.org/10.1016/0021-9614(85)90063-1
. [all data]
Inoue, Arai, et al., 1981
Inoue, Mikio; Arai, Yasuhiko; Saito, Shozaburo; Suzuki, Nobuo,
Vapor-liquid equilibriums of acetylacetone-organic solvent systems,
J. Chem. Eng. Data, 1981, 26, 3, 287-293, https://doi.org/10.1021/je00025a020
. [all data]
Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,
Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,
J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018
. [all data]
Houk, Davis, et al., 1973
Houk, K.N.; Davis, L.P.; Newkome, G.R.; Duke, R.E., Jr.; Nauman, R.V.,
Photoelectron spectroscopy of cyclic β-diketones their enolone tautomers,
J. Am. Chem. Soc., 1973, 95, 8364. [all data]
Shigorin, Filyugina, et al., 1967
Shigorin, D.N.; Filyugina, A.D.; Potapov, V.K.,
Role of intramolecular hydrogen bonding in the ionisation and dissociation of compounds,
Zh. Fiz. Khim., 1967, 41, 2336, In original 1255. [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]
Hush, Livett, et al., 1987
Hush, N.S.; Livett, M.K.; Peel, J.B.; Willett, G.D.,
Variable-temperature ultraviolet photoelectron spectroscopy of the keto-enol tautomers of pentane-2,4-dione,
Aust. J. Chem., 1987, 40, 599. [all data]
Cauletti, Furlani, et al., 1980
Cauletti, C.; Furlani, C.; Storto, G.,
Coordinative bond d-shell ionisations in the UV photoelectron spectra of bis({beta}-diketonato) cobalt (II) copper (II) complexes, their thio analogues,
J. Electron Spectrosc. Relat. Phenom., 1980, 18, 329. [all data]
Schweig, Vermeer, et al., 1974
Schweig, A.; Vermeer, H.; Weidner, U.,
A photoelectron spectroscopic study of keto-enol tautomerism in acetylacetones - a new application of photoelectron spectroscopy,
Chem. Phys. Lett., 1974, 26, 229. [all data]
Evans, Hamnett, et al., 1972
Evans, S.; Hamnett, A.; Orchard, A.F.; Lloyd, D.R.,
Study of the metal-oxygen bond in simple tris-chelate complexes by He(I) photoelectron spectroscopy,
Faraday Discuss. Chem. Soc., 1972, 54, 227. [all data]
Reichert and Westmore, 1969
Reichert, C.; Westmore, J.B.,
Mass spectral studies of metal chelates. IV.Mass spectra, appearance potentials, and coordinate bond energies of bis(acetylacetonate)metal(II) complexes of the first transition series,
Inorg. Chem., 1969, 8, 1012. [all data]
Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G.,
Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase,
Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005
. [all data]
Strohmeier and Höhne, 1952
Strohmeier, W.; Höhne, I.,
Keto-Enol-Umwandlung des Acetylacteons in Gaszustand,
Z. Naturfor., 1952, 7B, 184. [all data]
Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P.,
Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A),
Can. J. Chem., 1978, 56, 1. [all data]
Folkendt, Weiss-Lopez, et al., 1989
Folkendt, M.M.; Weiss-Lopez, B.E.; Chauvel, J.P., Jr.; True, N.S.,
Gas-Phase 1H NMR Studies of Keto-Enol Tautomerization of Acetylacetone, Methyl Acetoacetate, and Ethyl Acetoacetate,
J. Phys. Chem., 1989, 89, 15, 3347, https://doi.org/10.1021/j100261a038
. [all data]
Irikura, 1999
Irikura, K.K.,
Acetylacetonate (acac) anion in the gas phase: predicted structures, vibrational spectra, and photodetachment energies,
Int. J. Mass Spectrom., 1999, 187, 577-587, https://doi.org/10.1016/S1387-3806(98)14192-1
. [all data]
French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P.,
Hydrogen bonding of O-H and C-H hydrogen donors to Cl-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl- = RHCl-,
Can. J. Chem., 1982, 60, 1907. [all data]
Caldwell, Masucci, et al., 1989
Caldwell, G.W.; Masucci, J.A.; Ikonomou, M.G.,
Negative Ion Chemical Ionization Mass Spectrometry - Binding of Molecules to Bromide and Iodide Anions,
Org. Mass Spectrom., 1989, 24, 1, 8, https://doi.org/10.1002/oms.1210240103
. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, Ion clustering data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy T Temperature Tboil Boiling point Tfus Fusion (melting) point Ttriple Triple point temperature ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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