1,2-Butadiene, 3-methyl-
- Formula: C5H8
- Molecular weight: 68.1170
- IUPAC Standard InChI: InChI=1S/C5H8/c1-4-5(2)3/h1H2,2-3H3
- IUPAC Standard InChIKey: PAKGDPSCXSUALC-UHFFFAOYSA-N
- CAS Registry Number: 598-25-4
- 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: 1,1-Dimethylallene; 1,1-Dimethylallylene; 2-Methyl-2,3-butadiene; 3-Methyl-1,2-butadiene; 3,3-Dimethylallene; CH2=C=C(CH3)2; 3-methylbuta-1,2-diene
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Condensed phase 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:
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 |
|---|---|---|---|---|---|
| ΔfH°liquid | 24.18 ± 0.12 | kcal/mol | Ccb | Good, 1969 | ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°liquid | -767.70 ± 0.10 | kcal/mol | Ccb | Good, 1969 | Corresponding ΔfHºliquid = 24.18 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid | 55.399 | cal/mol*K | N/A | Messerly, Todd, et al., 1970 | DH |
Constant pressure heat capacity of liquid
| Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 36.429 | 298.15 | Messerly, Todd, et al., 1970 | T = 12 to 320 K.; DH |
| 36.11 | 298.15 | Good, 1969 | DH |
Gas phase ion energetics data
Go To: Top, Condensed phase 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 by: Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
View reactions leading to C5H8+ (ion structure unspecified)
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 8.9 | EI | Harris, McKinnon, et al., 1979 | |
| 8.95 ± 0.02 | PE | Bieri, Burger, et al., 1977 | |
| 8.95 | PE | Brogli, Crandall, et al., 1973 | Vertical value |
References
Go To: Top, Condensed phase 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.
Good, 1969
Good, W.D.,
3-Methyl-1,2-butadiene: Enthalpies of combustion and formation,
J. Chem. Eng. Data, 1969, 14, 480-481. [all data]
Messerly, Todd, et al., 1970
Messerly, J.F.; Todd, S.S.; Guthrie, G.B.,
Chemical thermodynamic properties of the pentadienes,
J. Chem. Eng. Data, 1970, 15, 227-232. [all data]
Harris, McKinnon, et al., 1979
Harris, D.; McKinnon, S.; Boyd, R.K.,
The origins of the base peak in the electron impact spectrum of limonene,
Org. Mass Spectrom., 1979, 14, 265. [all data]
Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P.,
Valence ionization enrgies of hydrocarbons,
Helv. Chim. Acta, 1977, 60, 2213. [all data]
Brogli, Crandall, et al., 1973
Brogli, F.; Crandall, J.K.; Heilbronner, E.; Kloster-Jensen, E.; Sojka, S.A.,
The photoelectron spectra of methyl-substituted allenes and of tetramethyl-bisallenyl,
J. Electron Spectrosc. Relat. Phenom., 1973, 2, 455. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,liquid Constant pressure heat capacity of liquid S°liquid Entropy of liquid at standard conditions ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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