2-Pentene, (E)-

Formula: C₅H₁₀
Molecular weight: 70.1329
IUPAC Standard InChI: InChI=1S/C5H10/c1-3-5-4-2/h3,5H,4H2,1-2H3/b5-3+
IUPAC Standard InChIKey: QMMOXUPEWRXHJS-HWKANZROSA-N
CAS Registry Number: 646-04-8
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.
Stereoisomers:
- 2-Pentene
- 2-Pentene, (Z)-
Other names: trans-2-Pentene; (E)-2-Pentene; trans-β-Amylene; 2-trans-Pentene; 2-(E)-C5H10; 2-Pentene, trans-; Pentene-2, trans-; trans-pent-2-ene
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
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	-32. ± 2.	kJ/mol	AVG	N/A	Average of 7 values; Individual data points

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
108.9	298.15	Thermodynamics Research Center, 1997	p=1 bar. Recommended values were calculated from data for lower alkenes by a method of increments. These values are in good agreement with experimental data (see also [ Kilpatrick J.E., 1946]).; GT
109.4	300.
136.6	400.
162.0	500.
184.2	600.
203.4	700.
220.0	800.
234.3	900.
246.8	1000.
257.6	1100.
267.0	1200.
275.2	1300.
282.2	1400.
288.40	1500.

Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	-58.24 ± 0.42	kJ/mol	Eqk	Wiberg, Wasserman, et al., 1984	Trifluoroacetolysis; ALS
Δ_fH°_liquid	-57.98 ± 0.76	kJ/mol	Ccb	Good and Smith, 1979	ALS
Δ_fH°_liquid	-59.7 ± 1.0	kJ/mol	Chyd	N/A	DRB
Δ_fH°_liquid	-60.8 ± 0.4	kJ/mol	Cm	Coops, Mulder, et al., 1946	DRB
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-3338.71 ± 0.70	kJ/mol	Ccb	Good and Smith, 1979	Corresponding Δ_fHº_liquid = -57.99 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-3335.9 ± 0.42	kJ/mol	Cm	Coops, Mulder, et al., 1946	Reanalyzed by Cox and Pilcher, 1970, Original value = -3334.6 ± 0.08 kJ/mol; Corresponding Δ_fHº_liquid = -60.79 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	256.6	J/mol*K	N/A	Chao, Hall, et al., 1983	DH
S°_liquid	256.52	J/mol*K	N/A	Todd, Oliver, et al., 1947	DH

Constant pressure heat capacity of liquid

C_p,liquid (J/mol*K)	Temperature (K)	Reference	Comment
157.0	298.15	Chao, Hall, et al., 1983	T = 12 to 302 K.; DH
156.98	298.15	Todd, Oliver, et al., 1947	T = 12 to 300 K.; DH

Reaction thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
RCD - Robert C. Dunbar

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Individual Reactions

= 2-Pentene, (E)-

By formula: C₅H₁₀ = C₅H₁₀

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-4.90 ± 0.08	kJ/mol	Eqk	Kapteijn, Steen, et al., 1983	gas phase; Between 250-823 K; ALS
Δ_rH°	-4. ± 0.63	kJ/mol	Eqk	Egger and Benson, 1966	gas phase; Heat of isomerization; ALS

2-Pentene, (E)- =

By formula: C₅H₁₀ = C₅H₁₀

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-10.9 ± 0.8	kJ/mol	Eqk	Egger and Benson, 1966	gas phase; Heat of Isomerization; ALS

+ 2-Pentene, (E)- =

By formula: H₂ + C₅H₁₀ = C₅H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-113.8 ± 0.8	kJ/mol	Chyd	Egger and Benson, 1966	gas phase; ALS

= 2-Pentene, (E)- +

By formula: C₅H₁₁Cl = C₅H₁₀ + HCl

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	62.3	kJ/mol	Eqk	Karaseva and Andreevskii, 1969	gas phase; ALS

+ 2-Pentene, (E)- = ( • )

By formula: Ag⁺ + C₅H₁₀ = (Ag⁺ • C₅H₁₀)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	158. ± 19.	kJ/mol	RAK	Ho, Yang, et al., 1997	RCD

Gas phase ion energetics data

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Data evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard

View reactions leading to C₅H₁₀⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	9.04 ± 0.01	eV	N/A	N/A	L

Ionization energy determinations

IE (eV)	Method	Reference	Comment
9.04 ± 0.02	PE	Bieri, Burger, et al., 1977	LLK
9.036 ± 0.005	PE	Masclet, Grosjean, et al., 1973	LLK
8.92	EI	Lossing, 1972	LLK
9.32 ± 0.03	EI	Gross and Wilkins, 1971	LLK
9.06	EI	Collin and Lossing, 1959	RDSH
9.23 ± 0.01	PE	Krause, Taylor, et al., 1978	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₃H₆⁺	11.73 ± 0.11	C₂H₄	EI	Gross and Wilkins, 1971	LLK
C₄H₇⁺	10.68	CH₃	EI	Brand and Baer, 1984	LBLHLM
C₄H₇⁺	10.68	CH₃	EI	Lossing, 1972	LLK
C₄H₇⁺	11.35 ± 0.03	CH₃	EI	Gross and Wilkins, 1971	LLK

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Notes

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]

Kilpatrick J.E., 1946
Kilpatrick J.E., Heats, equilibrium constants, and free energies of formation of the monoolefin hydrocarbons, J. Res. Nat. Bur. Stand, 1946, 36, 559-612. [all data]

Wiberg, Wasserman, et al., 1984
Wiberg, K.B.; Wasserman, D.J.; Martin, E., Enthalpies of hydration of alkenes. 2. The n-heptenes and n-pentenes, J. Phys. Chem., 1984, 88, 3684-3688. [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]

Coops, Mulder, et al., 1946
Coops, J.; Mulder, D.; Dienske, J.W.; Smittenberg, J., The heats of combustion of a number of hydrocarbons, Rec. Trav. Chim. Pays/Bas, 1946, 65, 128. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [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]

Kapteijn, Steen, et al., 1983
Kapteijn, F.; Steen, A.J.; Mol, J.C., Thermodynamics of the geometrical isomerization of 2-butene and 2-pentene, J. Chem. Thermodyn., 1983, 15, 137-146. [all data]

Egger and Benson, 1966
Egger, K.W.; Benson, S.W., Nitric oxide and iodine catalyzed isomerization of olefins. VI. Thermodynamic data from equilibrium studies of the geometrical and positional isomerization of n-pentenes, J. Am. Chem. Soc., 1966, 88, 236-240. [all data]

Karaseva and Andreevskii, 1969
Karaseva, S.Ya.; Andreevskii, D.N., Equilibrium in the isomerisation of secondary monochloropentanes and the dehydrochlorination of 2-chloropentane, Russ. J. Phys. Chem. (Engl. Transl.), 1969, 43, 1236-1238. [all data]

Ho, Yang, et al., 1997
Ho, Y.-P.; Yang, Y.-C.; Klippenstein, S.J.; Dunbar, R.C., Binding Energies of Ag+ and Cd+ Complexes from Analysis of Radiative Association Kinetics, J. Phys. Chem. A, 1997, 101, 18, 3338, https://doi.org/10.1021/jp9637284 . [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]

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]

Collin and Lossing, 1959
Collin, J.; Lossing, F.P., Ionization potentials of some olefins, di-olefins and branched paraffins, J. Am. Chem. Soc., 1959, 81, 2064. [all data]

Krause, Taylor, et al., 1978
Krause, D.A.; Taylor, J.W.; Fenske, R.F., An analysis of the effects of alkyl substituents on the ionization potentials of n-alkenes, J. Am. Chem. Soc., 1978, 100, 718. [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

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Symbols used in this document:

AE	Appearance energy
C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
IE (evaluated)	Recommended ionization energy
S°_liquid	Entropy of liquid at standard conditions
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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