Propanal, 2-methyl-
- Formula: C4H8O
- Molecular weight: 72.1057
- IUPAC Standard InChIKey: AMIMRNSIRUDHCM-UHFFFAOYSA-N
- CAS Registry Number: 78-84-2
- 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: Isobutyraldehyde; α-Methylpropionaldehyde; Isobutanal; Isopropylaldehyde; Isopropylformaldehyde; 2-Methylpropanal; 2-Methylpropionaldehyde; iso-C3H7CHO; Isobutylaldehyde; Isobutyric aldehyde; 2-Methyl-1-propanal; Isobutyraldehyd; Propionaldehyde, 2-methyl-; Valine aldehyde; Isobutaldehyde; Isobutyryl aldehyde; Methyl propanal; NCI-C60968; UN 2045; Isobutyral; NSC 6739; 2-methylpropanal (isobutanal)
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Gas phase thermochemistry data
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -51.57 ± 0.37 | kcal/mol | Cm | Wiberg, Crocker, et al., 1991 | ALS |
ΔfH°gas | -51.72 | kcal/mol | N/A | Gubareva and Gerasimov, 1990 | Value computed using ΔfHliquid° value of -247.9±0.7 kj/mol from Gubareva and Gerasimov, 1990 and ΔvapH° value of 31.5 kj/mol from Connett, 1975.; DRB |
ΔfH°gas | -51.55 ± 0.31 | kcal/mol | Eqk | Connett, 1975 | Heat of dehydrogenation; ALS |
ΔfH°gas | -52.1 | kcal/mol | Ccb | Tjebbes, 1962 | ALS |
Reaction 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 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
C4H7O- + =
By formula: C4H7O- + H+ = C4H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 366.8 ± 3.0 | kcal/mol | D-EA | Alconcel, Deyerl, et al., 2001 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 359.5 ± 3.1 | kcal/mol | H-TS | Alconcel, Deyerl, et al., 2001 | gas phase; B |
By formula: H2 + C4H8O = C4H10O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -20.88 ± 0.08 | kcal/mol | Cm | Wiberg, Crocker, et al., 1991 | liquid phase; ALS |
ΔrH° | -16.3 ± 0.2 | kcal/mol | Eqk | Connett, 1975 | gas phase; Heat of dehydrogenation; ALS |
(CAS Reg. No. 35730-34-8 • 4294967295) + = CAS Reg. No. 35730-34-8
By formula: (CAS Reg. No. 35730-34-8 • 4294967295C4H8O) + C4H8O = CAS Reg. No. 35730-34-8
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 42.0 ± 2.2 | kcal/mol | N/A | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
By formula: C4H10O = H2 + C4H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 16.3 ± 0.2 | kcal/mol | Eqk | Connett, 1975 | gas phase; Heat of dehydrogenation; ALS |
By formula: C6H14O2 + H2O = 2CH4O + C4H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 8.698 ± 0.016 | kcal/mol | Eqk | Wiberg and Squires, 1981 | liquid phase; ALS |
By formula: H2O + C4H8O = C4H10O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -5.6 | kcal/mol | Eqk | Green and Hine, 1973 | liquid phase; ALS |
By formula: 3C4H8O = C12H24O3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -6.804 | kcal/mol | Eqk | Ogorodnikov, Katsnel'son, et al., 1990 | liquid phase; PMR; ALS |
By formula: C4H8O = C4H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -20.60 | kcal/mol | Kin | Farberov, Bondarenko, et al., 1984 | liquid phase; ALS |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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
View reactions leading to C4H8O+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 9.71 ± 0.02 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 190.6 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 183.0 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.72 | PI | Traeger and McAdoo, 1986 | LBLHLM |
9.705 ± 0.005 | PE | Hernandez, Masclet, et al., 1977 | LLK |
9.69 ± 0.01 | PE | Cocksey, Eland, et al., 1971 | LLK |
9.74 ± 0.03 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
9.82 | PE | Tam, Yee, et al., 1974 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C2H3O+ | 10.29 | C2H5 | PI | Traeger and McAdoo, 1986 | LBLHLM |
De-protonation reactions
C4H7O- + =
By formula: C4H7O- + H+ = C4H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 366.8 ± 3.0 | kcal/mol | D-EA | Alconcel, Deyerl, et al., 2001 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 359.5 ± 3.1 | kcal/mol | H-TS | Alconcel, Deyerl, et al., 2001 | gas phase; B |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center, 1998. |
NIST MS number | 291424 |
References
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Wiberg, Crocker, et al., 1991
Wiberg, K.B.; Crocker, L.S.; Morgan, K.M.,
Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups,
J. Am. Chem. Soc., 1991, 113, 3447-3450. [all data]
Gubareva and Gerasimov, 1990
Gubareva, A.I.; Gerasimov, P.A.,
Physicochemical properties of isobutyraldehyde,
J. Appl. Chem. USSR, 1990, 63, 844-846. [all data]
Connett, 1975
Connett, J.E.,
Chemical equilibria 6. Measurement of equilibrium constants for the dehydrogenation of 2-methylpropan-1-ol by a vapour-flow technique,
J. Chem. Thermodyn., 1975, 7, 1159-1162. [all data]
Tjebbes, 1962
Tjebbes, J.,
Heats of combustion of propanal and 2-methyl propanal,
Acta Chem. Scand., 1962, 16, 953-857. [all data]
Alconcel, Deyerl, et al., 2001
Alconcel, L.S.; Deyerl, H.J.; Continetti, R.E.,
Effects of alkyl substitution on the energetics of enolate anions and radicals,
J. Am. Chem. Soc., 2001, 123, 50, 12675-12681, https://doi.org/10.1021/ja0120431
. [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]
Wiberg and Squires, 1981
Wiberg, K.B.; Squires, R.R.,
Thermochemical studies of carbonyl reactions. 2. Steric effects in acetal and ketal hydrolysis,
J. Am. Chem. Soc., 1981, 103, 4473-4478. [all data]
Green and Hine, 1973
Green, L.R.; Hine, J.,
Isobutyraldehyde. The kinetics of acid- and base-catalyzed equilibrations in water,
J. Org. Chem., 1973, 38, 2801-28. [all data]
Ogorodnikov, Katsnel'son, et al., 1990
Ogorodnikov, A.L.; Katsnel'son, M.G.; Pinson, V.V.; Levin, Yu.V.,
Study of thermodynamic characteristics of a butyraldehyde-cyclic trimer system,
Zh. Prikl. Khim. (Leningrad), 1990, 63, 1340-1343. [all data]
Farberov, Bondarenko, et al., 1984
Farberov, M.I.; Bondarenko, A.V.; Tsilyurik, T.V.; Srednev, S.S.; Shutova, I.A.,
Epoxidation of isobutene with organic hydroperoxides, and certain syntheses on this basis,
J. Anal. Chem. USSR, 1984, 57, 1915-1919. [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]
Traeger and McAdoo, 1986
Traeger, J.C.; McAdoo, D.J.,
Decomposition thresholds and associated translational energy releases for eight C4H8O+ isomers,
Int. J. Mass Spectrom. Ion Processes, 1986, 68, 35. [all data]
Hernandez, Masclet, et al., 1977
Hernandez, R.; Masclet, P.; Mouvier, G.,
Spectroscopie de photoelectrons d'aldehydes et de cetones aliphatiques,
J. Electron Spectrosc. Relat. Phenom., 1977, 10, 333. [all data]
Cocksey, Eland, et al., 1971
Cocksey, B.J.; Eland, J.H.D.; Danby, C.J.,
The effect of alkyl substitution on ionisation potential,
J. Chem. Soc., 1971, (B), 790. [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]
Tam, Yee, et al., 1974
Tam, W.-C.; Yee, D.; Brion, C.E.,
Photoelectron spectra of some aldehydes and ketones,
J. Electron Spectrosc. Relat. Phenom., 1974, 4, 77. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy ΔfH°gas Enthalpy of formation of gas at standard conditions 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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