Cyclopentane, methyl-

Formula: C₆H₁₂
Molecular weight: 84.1595
IUPAC Standard InChI: InChI=1S/C6H12/c1-6-4-2-3-5-6/h6H,2-5H2,1H3
IUPAC Standard InChIKey: GDOPTJXRTPNYNR-UHFFFAOYSA-N
CAS Registry Number: 96-37-7
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: Methylcyclopentane; UN 2298
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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	-106.0	kJ/mol	N/A	Good and Smith, 1969	Value computed using Δ_fH_liquid° value of -137.7±0.7 kj/mol from Good and Smith, 1969 and Δ_vapH° value of 31.7 kj/mol from Prosen, Johnson, et al., 1946.; DRB
Δ_fH°_gas	-106.7 ± 0.84	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	ALS
Δ_fH°_gas	-108.1	kJ/mol	N/A	Moore, Renquist, et al., 1940	Value computed using Δ_fH_liquid° value of -139.8±1.7 kj/mol from Moore, Renquist, et al., 1940 and Δ_vapH° value of 31.7 kj/mol from Prosen, Johnson, et al., 1946.; DRB

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
43.31	50.	Thermodynamics Research Center, 1997	p=1 bar. Selected values of S(T) and Cp(T) are in close agreement with those calculated by [ Scott D.W., 1960] at low temperatures. Discrepancies increase up to 1.8 J/mol*K at 1000-1500 K.; GT
53.01	100.
62.63	150.
74.75	200.
99.62	273.15
109.5	298.15
110.3	300.
151.5	400.
188.9	500.
220.3	600.
246.6	700.
268.6	800.
287.4	900.
303.4	1000.
317.1	1100.
328.9	1200.
339.0	1300.
347.8	1400.
355.4	1500.
370.4	1750.
381.1	2000.
389.1	2250.
395.1	2500.
399.7	2750.
403.3	3000.

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
124.24 ± 0.25	333.20	McCullough J.P., 1959	GT
136.21 ± 0.27	362.55
152.15 ± 0.30	402.35
165.21 ± 0.33	436.25
178.17 ± 0.36	471.05

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, References, Notes

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	-137.7 ± 0.71	kJ/mol	Ccb	Good and Smith, 1969	ALS
Δ_fH°_liquid	-138.4 ± 0.84	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	ALS
Δ_fH°_liquid	-139.8 ± 1.7	kJ/mol	Ccb	Moore, Renquist, et al., 1940	Reanalyzed by Cox and Pilcher, 1970, Original value = -141.1 kJ/mol; see Moore and Parks, 1939; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-3938.3 ± 0.59	kJ/mol	Ccb	Good and Smith, 1969	Corresponding Δ_fHº_liquid = -137.7 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-3937.7 ± 0.75	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	Corresponding Δ_fHº_liquid = -138.3 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-3936.2 ± 1.7	kJ/mol	Ccb	Moore, Renquist, et al., 1940	Reanalyzed by Cox and Pilcher, 1970, Original value = -3934.5 ± 1.7 kJ/mol; see Moore and Parks, 1939; Corresponding Δ_fHº_liquid = -139.8 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-3956.	kJ/mol	Ccb	Zubova, 1901	Corresponding Δ_fHº_liquid = -120. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	247.78	J/mol*K	N/A	Douslin and Huffman, 1946	DH
S°_liquid	247.7	J/mol*K	N/A	Huffman, Parks, et al., 1931	Extrapolation below 90 K, 57.86 J/mol*K.; DH

Constant pressure heat capacity of liquid

C_p,liquid (J/mol*K)	Temperature (K)	Reference	Comment
157.66	293.15	Siddiqi, Svejda, et al., 1983	DH
159.12	299.8	Connolly, Sage, et al., 1951	T = 80 to 200°F.; DH
158.70	298.15	Douslin and Huffman, 1946	T = 12 to 300 K.; DH
157.3	295.7	Huffman, Parks, et al., 1931	T = 92 to 294 K. Value is unsmoothed experimental datum.; DH

Reaction thermochemistry data

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Data compiled by: 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

+ = Cyclopentane, methyl-

By formula: H₂ + C₆H₁₀ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-100.8 ± 0.63	kJ/mol	Chyd	Rogers, Crooks, et al., 1987	liquid phase
Δ_rH°	-101.3 ± 0.50	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957, 2	liquid phase; solvent: Acetic acid

+ = Cyclopentane, methyl-

By formula: H₂ + C₆H₁₀ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-115.9 ± 0.96	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane
Δ_rH°	-112.5 ± 0.08	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid
Δ_rH°	-112.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid
Δ_rH°	-112.2 ± 0.3	kJ/mol	Chyd	Turner and Garner, 1957, 2	liquid phase; solvent: Acetic acid

+ = Cyclopentane, methyl-

By formula: C₆H₁₀ + H₂ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-115.4 ± 0.75	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane

Cyclopentane, methyl- =

By formula: C₆H₁₂ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-14.69	kJ/mol	Eqk	Glasebrook and Lovell, 1939	liquid phase; Heat of isomerization

2 + = Cyclopentane, methyl-

By formula: 2H₂ + C₆H₈ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-264. ± 0.8	kJ/mol	Chyd	Roth, Adamczak, et al., 1991	liquid phase

3 + = Cyclopentane, methyl-

By formula: 3H₂ + C₆H₆ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-330. ± 0.4	kJ/mol	Chyd	Roth, Adamczak, et al., 1991	liquid phase

2 + = Cyclopentane, methyl-

By formula: 2H₂ + C₆H₈ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-221. ± 0.8	kJ/mol	Chyd	Roth, Adamczak, et al., 1991	liquid phase

= Cyclopentane, methyl-

By formula: C₆H₁₂ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	18.1 ± 1.2	kJ/mol	Eqk	Kabo and Andreevskii, 1973	liquid phase

References

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

Good and Smith, 1969
Good, W.D.; Smith, N.K., Enthalpies of combustion of toluene, benzene, cyclohexane, cyclohexene, methylcyclopentane, 1-methylcyclopentene, and n-hexane, J. Chem. Eng. Data, 1969, 14, 102-106. [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]

Moore, Renquist, et al., 1940
Moore, G.E.; Renquist, M.L.; Parks, G.S., Thermal data on organic compounds. XX. Modern combustion data for two methylnonanes, methyl ethyl ketone, thiophene and six cycloparaffins, J. Am. Chem. Soc., 1940, 62, 1505-1507. [all data]

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]

Scott D.W., 1960
Scott D.W., Chemical thermodynamic properties of methylcyclopentane and 1-cis-3-dimethylcyclopentane, J. Phys. Chem., 1960, 64, 906-908. [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]

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

Moore and Parks, 1939
Moore, G.E.; Parks, G.S., New thermodynamic data for the cyclohexane-methylcyclopentane isomerization, J. Am. Chem. Soc., 1939, 61, 2561-2562. [all data]

Zubova, 1901
Zubova, P., Data about heat of combustion of compound cycle structure, Zh. Fiz. Khim., 1901, 33, 708-722. [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]

Huffman, Parks, et al., 1931
Huffman, H.M.; Parks, G.S.; Barmore, M., Thermal data on organic compounds. X. Further studies on the heat capacities, entropies and free energies of hydrocarbons, J. Am. Chem. Soc., 1931, 53, 3876-3888. [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]

Connolly, Sage, et al., 1951
Connolly, T.J.; Sage, B.H.; Lacey, W.N., Isobaric heat capacities at bubble point. n-Hexane, methylcyclopentane, and n-octane, Ind. Eng. Chem., 1951, 43, 946-950. [all data]

Rogers, Crooks, et al., 1987
Rogers, D.W.; Crooks, E.; Dejroongruang, K., Enthalpies of hydrogenation of the hexenes, J. Chem. Thermodyn., 1987, 19, 1209-1215. [all data]

Allinger, Dodziuk, et al., 1982
Allinger, N.L.; Dodziuk, H.; Rogers, D.W.; Naik, S.N., Heats of hydrogenation and formation of some 5-membered ring compounds by molecular mechanics calculations and direct measurements, Tetrahedron, 1982, 38, 1593-1597. [all data]

Turner and Garner, 1958
Turner, R.B.; Garner, R.H., Heats of hydrogenation. V. Relative stabilities in certain exocyclic-endocyclic olefin pairs, J. Am. Chem. Soc., 1958, 80, 1424-1430. [all data]

Turner and Garner, 1957
Turner, R.B.; Garner, R.H., Heats of hydrogenation. V. Relative stabilities in certain exocyclic-endocyclic olefin pairs, J. Am. Chem. Soc., 1957, 80, 1424-1430. [all data]

Turner and Garner, 1957, 2
Turner, R.B.; Garner, R.H., The stability relationship of 1-methyl-cyclopentene and methylenecyclopentane, J. Am. Chem. Soc., 1957, 79, 253. [all data]

Glasebrook and Lovell, 1939
Glasebrook, A.L.; Lovell, W.G., The isomerization of cyclohexane and methylcyclopentane, J. Am. Chem. Soc., 1939, 61, 1717-1720. [all data]

Roth, Adamczak, et al., 1991
Roth, W.R.; Adamczak, O.; Breuckmann, R.; Lennartz, H.-W.; Boese, R., Die Berechnung von Resonanzenergien; das MM2ERW-Kraftfeld, Chem. Ber., 1991, 124, 2499-2521. [all data]

Kabo and Andreevskii, 1973
Kabo, G.Ya.; Andreevskii, D.N., Thermodynamic characteristics of the cyclohexane = methylcyclopentane isomerization, Zh. Fiz. Khim., 1973, 47, 272-273. [all data]

Notes

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Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
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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