Cyclopentane

Formula: C₅H₁₀
Molecular weight: 70.1329
IUPAC Standard InChI: InChI=1S/C5H10/c1-2-4-5-3-1/h1-5H2
IUPAC Standard InChIKey: RGSFGYAAUTVSQA-UHFFFAOYSA-N
CAS Registry Number: 287-92-3
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: Pentamethylene; UN 1146
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Gas phase thermochemistry data

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

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
Δ_fH°_gas	-18.26 ± 0.19	kcal/mol	Ccb	McCullough, Pennington, et al., 1959	ALS
Δ_fH°_gas	-18.4	kcal/mol	N/A	Spitzer and Huffman, 1947	Value computed using Δ_fH_liquid° value of -105.6±1.8 kj/mol from Spitzer and Huffman, 1947 and Δ_vapH° value of 28.7 kj/mol from Prosen, Johnson, et al., 1946.; DRB
Δ_fH°_gas	-18.46 ± 0.18	kcal/mol	Ccb	Prosen, Johnson, et al., 1946	ALS

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
8.982	50.	Dorofeeva O.V., 1986	Recommended values are in good agreement with those calculated by [ Kilpatrick J.E., 1947, McCullough J.P., 1959] at low temperatures. The discrepancies increase at higher temperatures and amount to 1.8 J/molK for S(1500 K) and 2.1 J/molK for Cp(1500 K) obtained by [ McCullough J.P., 1959]. Calculation [ Sundaram S., 1963] seems to be incorrect because discrepancies with these data reach 23 and 7 J/mol*K for S(T) and Cp(T), respectively.; GT
9.603	100.
10.83	150.
12.95	200.
17.80	273.15
19.78 ± 0.48	298.15
19.93	300.
28.239	400.
35.863	500.
42.321	600.
47.729	700.
52.294	800.
56.171	900.
59.484	1000.
62.323	1100.
64.761	1200.
66.862	1300.
68.676	1400.
70.249	1500.

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
22.46 ± 0.045	329.05	McCullough J.P., 1959	Please also see Spitzer R., 1946.; GT
24.38 ± 0.20	353.
25.85 ± 0.20	372.
28.03 ± 0.30	395.
27.985 ± 0.055	395.05
30.19 ± 0.30	424.
33.16 ± 0.30	463.
33.334 ± 0.067	463.10
36.02 ± 0.40	503.
38.26 ± 0.40	539.

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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	-25.23 ± 0.42	kcal/mol	Ccb	Spitzer and Huffman, 1947	ALS
Δ_fH°_liquid	-25.31 ± 0.18	kcal/mol	Ccb	Prosen, Johnson, et al., 1946	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-786.7 ± 0.1	kcal/mol	Ccb	Kaarsemaker and Coops, 1952	Corresponding Δ_fHº_liquid = -25.17 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-786.62 ± 0.30	kcal/mol	Ccb	Spitzer and Huffman, 1947	Corresponding Δ_fHº_liquid = -25.21 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-786.54 ± 0.17	kcal/mol	Ccb	Prosen, Johnson, et al., 1946	Corresponding Δ_fHº_liquid = -25.29 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	48.791	cal/mol*K	N/A	Douslin and Huffman, 1946	DH
S°_liquid	48.870	cal/mol*K	N/A	Aston, Fink, et al., 1943	DH
S°_liquid	49.40	cal/mol*K	N/A	Jacobs and Parks, 1934	Extrapolation below 90 K, 53.09 J/mol*K.; DH

Constant pressure heat capacity of liquid

C_p,liquid (cal/mol*K)	Temperature (K)	Reference	Comment
30.292	298.15	Tanaka, 1985	DH
30.155	293.15	Siddiqi, Svejda, et al., 1983	DH
30.3234	298.15	Fortier, D'Arcy, et al., 1979	DH
30.421	298.15	Jolicoeur, Boileau, et al., 1975	DH
30.459	300.	Szasz, Morrison, et al., 1947	T = 14 to 300 K.; DH
30.301	298.15	Douslin and Huffman, 1946	T = 12 to 300 K.; DH
30.791	298.15	Aston, Fink, et al., 1943	T = 15 to 300 K.; DH
30.091	293.7	Jacobs and Parks, 1934	T = 93 to 294 K. Value is unsmoothed experimental datum.; DH

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:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
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)	10.33 ± 0.15	eV	N/A	N/A	L

Ionization energy determinations

IE (eV)	Method	Reference	Comment
9.83 ± 0.05	EI	Holmes and Lossing, 1991	LL
10.35	PI	Traeger, 1986	LBLHLM
10.33 ± 0.15	EQ	Mautner(Meot-Ner), Sieck, et al., 1981	LLK
10.3 ± 0.1	PE	Bieri, Burger, et al., 1977	LLK
10.55 ± 0.03	PE	Rang, Paldoia, et al., 1974	LLK
10.54 ± 0.05	EI	Puttemans, 1974	LLK
10.48	PE	Puttemans, 1974	LLK
10.40	PE	Ikuta, Yoshihara, et al., 1973	LLK
10.49	EI	Lossing, 1972	LLK
10.91 ± 0.07	EI	Gross and Wilkins, 1971	LLK
10.50 ± 0.01	PE	Praet and Delwiche, 1970	RDSH
10.49	PI	Dewar and Worley, 1969	RDSH
10.53 ± 0.05	PE	Watanabe, Nakayama, et al., 1962	RDSH
11.01	PE	Kimura, Katsumata, et al., 1981	Vertical value; LLK
10.7 ± 0.1	PE	Bieri, Burger, et al., 1977	Vertical value; LLK
10.5	PE	Batich, Heilbronner, et al., 1974	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₃H₆⁺	11.22 ± 0.04	C₂H₄	PI	Brand and Baer, 1984	LBLHLM
C₃H₆⁺	11.45	C₂H₄	EI	Puttemans, 1974	LLK
C₃H₆⁺	11.74 ± 0.07	C₂H₄	EI	Gross and Wilkins, 1971	LLK
C₄H₇⁺	11.08	CH₃	PI	Traeger, 1986	LBLHLM
C₄H₇⁺	11.15 ± 0.03	CH₃	PI	Brand and Baer, 1984	LBLHLM
C₄H₇⁺	11.14	CH₃	EI	Brand and Baer, 1984	LBLHLM
C₄H₇⁺	11.14	CH₃	EI	Lossing, 1972	LLK
C₄H₇⁺	11.36 ± 0.08	CH₃	EI	Gross and Wilkins, 1971	LLK

De-protonation reactions

C₅H₉^- + = Cyclopentane

By formula: C₅H₉^- + H⁺ = C₅H₁₀

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	416.1 ± 2.0	kcal/mol	Bran	DePuy, Gronert, et al., 1989	gas phase; B
Δ_rH°	418.3 ± 2.0	kcal/mol	Bran	Peerboom, Rademaker, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	407.4 ± 2.1	kcal/mol	H-TS	DePuy, Gronert, et al., 1989	gas phase; B
Δ_rG°	409.6 ± 2.1	kcal/mol	H-TS	Peerboom, Rademaker, et al., 1992	gas phase; B

References

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

McCullough, Pennington, et al., 1959
McCullough, J.P.; Pennington, R.E.; Smith, J.C.; Hossenlopp, I.A.; Waddington, G., Thermodynamics of cyclopentane, methylcyclopentane and 1,cis-3-dimethylcyclopentane: Verification of the concept of pseudorotation, J. Am. Chem. Soc., 1959, 81, 5880-5883. [all data]

Spitzer and Huffman, 1947
Spitzer, R.; Huffman, H.M., The heats of combustion of cyclopentane, cyclohexane, cycloheptane and cyclooctane, J. Am. Chem. Soc., 1947, 69, 211-213. [all data]

Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D., Heats of formation and combustion of the normal alkylcyclopentanes and cyclohexanes and the increment per CH₂ group for several homologous series of hydrocarbons, J. Res. NBS, 1946, 37, 51-56. [all data]

Dorofeeva O.V., 1986
Dorofeeva O.V., Thermodynamic properties of twenty-one monocyclic hydrocarbons, J. Phys. Chem. Ref. Data, 1986, 15, 437-464. [all data]

Kilpatrick J.E., 1947
Kilpatrick J.E., The thermodynamics and molecular structure of cyclopentane, J. Am. Chem. Soc., 1947, 69, 2483-2488. [all data]

McCullough J.P., 1959
McCullough J.P., Thermodynamics of cyclopentane, methylcyclopentane and 1,cis-3-dimethylcyclopentane: verification of the concept of pseudorotation, J. Am. Chem. Soc., 1959, 81, 5880-5883. [all data]

Sundaram S., 1963
Sundaram S., Thermodynamic functions of some propellants, Z. Phys. Chem. (Frankfurt), 1963, 36, 376-377. [all data]

Spitzer R., 1946
Spitzer R., The heat capacity of gaseous cyclopentane, cyclohexane and methylcyclohexane, J. Am. Chem. Soc., 1946, 68, 2537-2538. [all data]

Kaarsemaker and Coops, 1952
Kaarsemaker, S.; Coops, J., Thermal quantities of some cycloparaffins. Part III. Results of measurements, Rec. Trav. Chim. Pays/Bas, 1952, 71, 261. [all data]

Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M., The heat capacities, heats of transition, heats of fusion and entropies of cyclopentane, methylcyclopentane and methylcylohexane, J. Am. Chem. Soc., 1946, 68, 173-176. [all data]

Aston, Fink, et al., 1943
Aston, J.G.; Fink, H.L.; Schumann, S.C., The heat capacity and entropy, heats of transition, fusion and vaporization and the vapor pressures of cyclopentane. Evidence for a non-planar structure, J. Am. Chem. Soc., 1943, 65, 341-346. [all data]

Jacobs and Parks, 1934
Jacobs, C.J.; Parks, G.S., Thermal data on organic compounds. XIV. Some heat capacity, entropy and free energy data for cyclic substances, J. Am. Chem. Soc., 1934, 56, 1513-1517. [all data]

Tanaka, 1985
Tanaka, R., Excess heat capacities for mixtures of benzene with cyclopentane, methylcyclohexane, and cyclooctane at 298.15 K, J. Chem. Eng. Data, 1985, 30, 267-269. [all data]

Siddiqi, Svejda, et al., 1983
Siddiqi, M.A.; Svejda, P.; Kohler, F., A generalized van der Waals equation of state II. Excess heat capacities of mixtures containing cycloalkanes (C5,C6), methylcycloalkanes (C5,C6) and n-decane, Ber. Bunsenges. Phys. Chem., 1983, 87, 1176-1181. [all data]

Fortier, D'Arcy, et al., 1979
Fortier, J.-L.; D'Arcy, P.J.; Benson, G.C., Heat capacities of binary cycloalkane mixtures at 298.15 K, Thermochim. Acta, 1979, 28, 37-43. [all data]

Jolicoeur, Boileau, et al., 1975
Jolicoeur, C.; Boileau, J.; Bazinet, S.; Picker, P., Thermodynamic properties of aqueous organic solutes in relation to their structure. Part II. Apparent molal volumes and heat capacities of c-alkylamine hydrobromides in water, Can. J. Chem., 1975, 53, 716-722. [all data]

Szasz, Morrison, et al., 1947
Szasz, G.J.; Morrison, J.A.; Pace, E.L.; Aston, J.G., Thermal properties of cyclopentane and its use as a standard substance in low temperature thermal measurements, J. Chem. Phys., 1947, 15, 562-564. [all data]

Holmes and Lossing, 1991
Holmes, J.L.; Lossing, F.P., Ionization energies of homologous organic compounds and correlation with molecular size, Org. Mass Spectrom., 1991, 26, 537. [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]

Mautner(Meot-Ner), Sieck, et al., 1981
Mautner(Meot-Ner), M.; Sieck, L.W.; Ausloos, P., Ionization of normal alkanes: Enthalpy, entropy, structural, and isotope effects, J. Am. Chem. Soc., 1981, 103, 5342. [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]

Rang, Paldoia, et al., 1974
Rang, S.; Paldoia, P.; Talvari, A., Ionization potentials of unsaturated hydrocarbons. 2. Mono-substituted cyclopentenes and cyclohexenes, Eesti. NSV Tead. Akad. Toim., 1974, 354. [all data]

Puttemans, 1974
Puttemans, J.P., Ionisation de cycloalcanes (C₅ a C₁₂) en spectroscopie photoelectronique et par impact electronique, Ing. Chim. (Brussels), 1974, 56, 64. [all data]

Ikuta, Yoshihara, et al., 1973
Ikuta, S.; Yoshihara, K.; Shiokawa, T.; Jinno, M.; Yokoyama, Y.; Ikeda, S., Photoelectron spectroscopy of cyclohexane, cyclopentane, and some related compounds, Chem. Lett., 1973, 1237. [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]

Praet and Delwiche, 1970
Praet, M.-T.; Delwiche, J., Ionization energies of some cyclic molecules, Chem. Phys. Lett., 1970, 5, 546. [all data]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation, J. Chem. Phys., 1969, 50, 654. [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]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Batich, Heilbronner, et al., 1974
Batich, C.; Heilbronner, E.; Rommel, E.; Semmelhack, M.F.; Foos, J.S., Equivalence of the energy gaps {DELTA}I(1,2) and {DELTA}E(1,2) between corresponding bands in the photoelectron (I) and electronic absorption (E) spectra of spiro[4.4]nonatetraene. An amusing consequence of spiroconjugation, J. Am. Chem. Soc., 1974, 96, 7662. [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]

DePuy, Gronert, et al., 1989
DePuy, C.H.; Gronert, S.; Barlow, S.E.; Bierbaum, V.M.; Damrauer, R., The Gas Phase Acidities of the Alkanes, J. Am. Chem. Soc., 1989, 111, 6, 1968, https://doi.org/10.1021/ja00188a003 . [all data]

Peerboom, Rademaker, et al., 1992
Peerboom, R.A.L.; Rademaker, G.J.; Dekoning, L.J.; Nibbering, N.M.M., Stabilization of Cycloalkyl Carbanions in the Gas Phase, Rapid Commun. Mass Spectrom., 1992, 6, 6, 394, https://doi.org/10.1002/rcm.1290060608 . [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_rG°	Free energy of reaction 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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