2-Methyl-1-butene
- Formula: C5H10
- Molecular weight: 70.1329
- IUPAC Standard InChIKey: MHNNAWXXUZQSNM-UHFFFAOYSA-N
- CAS Registry Number: 563-46-2
- 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: 1-Butene, 2-methyl-; γ-Isoamylene; 1-Isoamylene; C2H5C(CH3)=CH2; 2-Methylbutene-1; Isopentene; UN 2371; UN 2459; 2-methylbut-1-ene
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Gas phase thermochemistry data
Go To: Top, Condensed phase 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -8.39 ± 0.20 | kcal/mol | Eqk | Wiberg and Hao, 1991 | Heat of hydration; ALS |
ΔfH°gas | -8.32 | kcal/mol | N/A | Good and Smith, 1979 | Value computed using ΔfHliquid° value of -60.96±0.84 kj/mol from Good and Smith, 1979 and ΔvapH° value of 26.19 kj/mol from missing citation.; DRB |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
24.610 | 273.15 | McCullough J.P., 1959 | Results of more recent statistical calculation [ Durig J.R., 1980] are different from recommended and experimental values up to 3 J/mol*K for S(T) and Cp(T).; GT |
26.281 | 298.15 | ||
26.410 | 300. | ||
33.200 | 400. | ||
39.400 | 500. | ||
44.720 | 600. | ||
49.259 | 700. | ||
53.150 | 800. | ||
56.520 | 900. | ||
59.431 | 1000. | ||
61.960 | 1100. | ||
64.149 | 1200. | ||
66.049 | 1300. | ||
67.710 | 1400. | ||
69.149 | 1500. |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
27.761 ± 0.084 | 320.66 | Scott D.W., 1949 | GT |
30.681 ± 0.093 | 362.51 | ||
33.61 ± 0.10 | 407.11 | ||
36.60 ± 0.11 | 453.41 | ||
39.52 ± 0.12 | 502.21 |
Condensed phase thermochemistry data
Go To: Top, Gas phase 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 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 | -14.57 ± 0.20 | kcal/mol | Ccb | Good and Smith, 1979 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -797.26 ± 0.19 | kcal/mol | Ccb | Good and Smith, 1979 | Corresponding ΔfHºliquid = -14.57 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 60.71 | cal/mol*K | N/A | Chao, Hall, et al., 1983 | DH |
S°liquid | 60.700 | cal/mol*K | N/A | Todd, Oliver, et al., 1947 | DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
37.60 | 298.15 | Chao, Hall, et al., 1983 | T = 12 to 293 K.; DH |
37.569 | 298.15 | Todd, Oliver, et al., 1947 | T = 12 to 300 K.; DH |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, 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 evaluated as indicated in comments:
L - Sharon G. Lias
Data compiled as indicated in comments:
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 C5H10+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 9.12 ± 0.01 | eV | N/A | N/A | L |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.10 | PI | Traeger, 1986 | LBLHLM |
9.148 ± 0.003 | PE | Masclet, Grosjean, et al., 1973 | LLK |
9.12 | EI | Lossing, 1972 | LLK |
9.35 ± 0.08 | EI | Gross and Wilkins, 1971 | LLK |
9.12 ± 0.02 | PI | Demeo and El-Sayed, 1970 | RDSH |
9.12 ± 0.02 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
9.2 ± 0.1 | PE | Bieri, Burger, et al., 1977 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C3H6+ | 11.66 ± 0.06 | C2H4 | EI | Gross and Wilkins, 1971 | LLK |
C4H7+ | 10.66 | CH3 | PI | Traeger, 1986 | LBLHLM |
C4H7+ | 10.85 | CH3 | EI | Brand and Baer, 1984 | LBLHLM |
C4H7+ | 10.85 | CH3 | EI | Lossing, 1972 | LLK |
C4H7+ | 11.34 ± 0.07 | CH3 | EI | Gross and Wilkins, 1971 | LLK |
References
Go To: Top, Gas phase thermochemistry data, 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.
Wiberg and Hao, 1991
Wiberg, K.B.; Hao, S.,
Enthalpies of hydration of alkenes. 4. Formation of acyclic tert-alcohols,
J. Org. Chem., 1991, 56, 5108-5110. [all data]
Good and Smith, 1979
Good, W.D.; Smith, N.K.,
The enthalpies of combustion of the isomeric pentenes in the liquid state. A warning to combustion calorimetrists about sample drying,
J. Chem. Thermodyn., 1979, 11, 111-118. [all data]
McCullough J.P., 1959
McCullough J.P.,
Thermodynamic properties, vibrational assignment and rotational conformations of 2-methyl-1-butene,
J. Am. Chem. Soc., 1959, 81, 1331-1334. [all data]
Durig J.R., 1980
Durig J.R.,
Torsional spectra of molecules with two internal C3v rotors. 19. Vibrational spectra, torsional potential functions, and conformational and thermodynamic properties of 2-methyl-1-butene,
J. Phys. Chem., 1980, 84, 3554-3561. [all data]
Scott D.W., 1949
Scott D.W.,
Thermodynamic properties of three isomeric pentenes,
J. Am. Chem. Soc., 1949, 71, 2767-2773. [all data]
Chao, Hall, et al., 1983
Chao, J.; Hall, K.R.; Yao, J.M.,
Thermodynamic properties of simple alkenes,
Thermochim. Acta, 1983, 64(3), 285-303. [all data]
Todd, Oliver, et al., 1947
Todd, S.S.; Oliver, G.D.; Huffman, H.M.,
The heat capacities, heats of fusion and entropies of the six pentenes,
J. Am. Chem. Soc., 1947, 69, 1519-1525. [all data]
Traeger, 1986
Traeger, J.C.,
Heat of formation for the 1-methylallyl cation by photoionization mass spectrometry,
J. Phys. Chem., 1986, 90, 4114. [all data]
Masclet, Grosjean, et al., 1973
Masclet, P.; Grosjean, D.; Mouvier, G.,
Alkene ionization potentials. Part I. Quantitative determination of alkyl group structural effects,
J. Electron Spectrosc. Relat. Phenom., 1973, 2, 225. [all data]
Lossing, 1972
Lossing, F.P.,
Free radicals by mass spectrometry. XLV. Ionization potentials and heats of formation of C3H3, C3H5, and C4H7 radicals and ions,
Can. J. Chem., 1972, 50, 3973. [all data]
Gross and Wilkins, 1971
Gross, M.L.; Wilkins, C.L.,
Computer-assisted ion cyclotron resonance appearance potential measurements for C5H10 isomers,
Anal. Chem., 1971, 43, 1624. [all data]
Demeo and El-Sayed, 1970
Demeo, D.A.; El-Sayed, M.A.,
Ionization potential and structure of olefins,
J. Chem. Phys., 1970, 52, 2622. [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]
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]
Brand and Baer, 1984
Brand, W.A.; Baer, T.,
Dissociation dynamics of energy-selected C5H10+ ions,
J. Am. Chem. Soc., 1984, 106, 3154. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid IE (evaluated) Recommended ionization energy S°liquid Entropy of liquid at standard conditions ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°gas Enthalpy of formation of gas 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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