Pentane, 2,2,4,4-tetramethyl-

Formula: C₉H₂₀
Molecular weight: 128.2551
IUPAC Standard InChI: InChI=1S/C9H20/c1-8(2,3)7-9(4,5)6/h7H2,1-6H3
IUPAC Standard InChIKey: GUMULFRCHLJNDY-UHFFFAOYSA-N
CAS Registry Number: 1070-87-7
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: Di-tert-Butylmethane; 2,2,4,4-Tetramethylpentane
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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, References, Notes

Data compiled as indicated in comments:
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	-241.5 ± 1.5	kJ/mol	Cm	Fuchs and Peacock, 1979	ALS
Quantity	Value	Units	Method	Reference	Comment
S°_gas	430.16	J/mol*K	N/A	Finke H.L., 1976	GT

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
153.72	200.	Scott D.W., 1974	Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT
198.95	273.15
214.6 ± 0.7	298.15
215.77	300.
276.56	400.
331.21	500.
379.07	600.
420.49	700.
456.47	800.
488.69	900.
516.72	1000.
541.41	1100.
563.58	1200.
581.58	1300.
602.50	1400.
619.23	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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-6117.8	kJ/mol	Ccb	Shtekher, Skuratov, et al., 1959	Corresponding Δ_fHº_liquid = -282. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-6118.7	kJ/mol	Ccb	Skuratov, Kozina, et al., 1958	Corresponding Δ_fHº_liquid = -281. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_liquid	-6119.9 ± 1.3	kJ/mol	Ccb	Johnson, Prosen, et al., 1947	Corresponding Δ_fHº_liquid = -280.0 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	331.8	J/mol*K	N/A	Finke, Messerly, et al., 1976	DH

Constant pressure heat capacity of liquid

C_p,liquid (J/mol*K)	Temperature (K)	Reference	Comment
266.3	298.15	Finke, Messerly, et al., 1976	T = 10 to 400 K.; DH

Phase change data

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

Data compiled as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
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
T_boil	395.4 ± 0.7	K	AVG	N/A	Average of 7 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
T_fus	207. ± 1.	K	AVG	N/A	Average of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
T_triple	206.61	K	N/A	Finke, Messerly, et al., 1976, 2	Uncertainty assigned by TRC = 0.02 K; TRC
Quantity	Value	Units	Method	Reference	Comment
T_c	574.6 ± 0.5	K	N/A	Daubert, 1996
T_c	574.65	K	N/A	Ambrose and Townsend, 1968	Uncertainty assigned by TRC = 0.1 K; TRC
Quantity	Value	Units	Method	Reference	Comment
P_c	24.9 ± 0.4	bar	N/A	Daubert, 1996
P_c	24.85	bar	N/A	Ambrose and Townsend, 1968	Uncertainty assigned by TRC = 0.10 bar; TRC
Quantity	Value	Units	Method	Reference	Comment
Δ_vapH°	38.55	kJ/mol	N/A	Majer and Svoboda, 1985
Δ_vapH°	38.5 ± 0.1	kJ/mol	C	Fuchs, Peacock, et al., 1982	AC
Δ_vapH°	38.5 ± 0.3	kJ/mol	C	Fuchs and Peacock, 1979	ALS
Δ_vapH°	38.5 ± 0.3	kJ/mol	GCC	Fuchs and Peacock, 1979	AC
Δ_vapH°	38.2	kJ/mol	N/A	Reid, 1972	See also Labbauf, Greenshields, et al., 1961.; AC

Enthalpy of vaporization

Δ_vapH (kJ/mol)	Temperature (K)	Method	Reference	Comment
32.51	395.5	N/A	Majer and Svoboda, 1985
37.2	328.	A	Stephenson and Malanowski, 1987	Based on data from 313. to 397. K. See also Forziati, Norris, et al., 1949.; AC
36.5	346.	EB	Smith, 1941	Based on data from 331. to 375. K. See also Boublik, Fried, et al., 1984.; AC
34.8	390.	N/A	Smith, 1941	Based on data from 375. to 422. K.; AC

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)

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Temperature (K)	A	B	C	Reference	Comment
316.11 to 396.42	3.92962	1329.863	-56.52	Forziati, Norris, et al., 1949, 2	Coefficents calculated by NIST from author's data.

Enthalpy of fusion

Δ_fusH (kJ/mol)	Temperature (K)	Reference	Comment
9.7441	206.61	Finke, Messerly, et al., 1976	DH
9.75	206.7	Domalski and Hearing, 1996	AC

Entropy of fusion

Δ_fusS (J/mol*K)	Temperature (K)	Reference	Comment
47.16	206.61	Finke, Messerly, et al., 1976	DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Notes

Fuchs and Peacock, 1979
Fuchs, R.; Peacock, L.A., Heats of vaporization and gaseous heats of formation of some five- and six-membered ring alkenes, Can. J. Chem., 1979, 57, 2302-2304. [all data]

Finke H.L., 1976
Finke H.L., Low-temperature thermal quantities for five alkyl-substituted pentanes, J. Chem. Thermodyn., 1976, 8, 965-983. [all data]

Scott D.W., 1974
Scott D.W., Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]

Scott D.W., 1974, 2
Scott D.W., Correlation of the chemical thermodynamic properties of alkane hydrocarbons, J. Chem. Phys., 1974, 60, 3144-3165. [all data]

Shtekher, Skuratov, et al., 1959
Shtekher, S.M.; Skuratov, S.M.; Daukshas, V.K.; Levina, R.Ya., Heats of combustion of some branched alkanes, Dokl. Akad. Nauk SSSR, 1959, 127, 812-814. [all data]

Skuratov, Kozina, et al., 1958
Skuratov, S.M.; Kozina, M.P.; Shtocher, S.M.; Prevalova, N.M.; Kamkina, L.S.; Zuko, V.D., Heats of combustion of cyclic compounds, Bull. Chem. Thermodyn., 1958, 1, 21. [all data]

Johnson, Prosen, et al., 1947
Johnson, W.H.; Prosen, E.J.; Rossini, F.D., Heats of combustion and isomerization of six nonanes, J. Res. NBS, 1947, 38, 419-422. [all data]

Finke, Messerly, et al., 1976
Finke, H.L.; Messerly, J.F.; Douslin, D.R., Low-temperature thermal quantities for five alkyl-substituted pentanes, J. Chem. Thermodynam., 1976, 8, 965-983. [all data]

Finke, Messerly, et al., 1976, 2
Finke, H.L.; Messerly, J.F.; Douslin, D.R., Low-Temp. Thermal Quantities for Five Alkyl-Substituted Pentanes, J. Chem. Thermodyn., 1976, 8, 965. [all data]

Daubert, 1996
Daubert, T.E., Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes, J. Chem. Eng. Data, 1996, 41, 365-372. [all data]

Ambrose and Townsend, 1968
Ambrose, D.; Townsend, R., Critical Temperatures and Pressures of Some Alkanes, Trans. Faraday Soc., 1968, 64, 2622. [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Fuchs, Peacock, et al., 1982
Fuchs, Richard; Peacock, L. Alan; Stephenson, W. Kirk, Enthalpies of interaction of polar and nonpolar molecules with aromatic solvents, Can. J. Chem., 1982, 60, 15, 1953-1958, https://doi.org/10.1139/v82-273 . [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Labbauf, Greenshields, et al., 1961
Labbauf, A.; Greenshields, J.B.; Rossini, F.D., Heats of formation, combustion, and vaporization of the 35 nonanes and 75 decanes, J. Chem. Eng. Data, 1961, 6, 261-263. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D., Vapor pressures and boiling points of sixty API-NBS hydrocarbons, J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050 . [all data]

Smith, 1941
Smith, E.R., Boiling points of benzene, 2,2,3-trimethylbutane, 3-ethylpentane, and 2,2,4,4-tetramethylpentane within the range 100 to 1,500 millimeters of mercury, J. RES. NATL. BUR. STAN., 1941, 26, 2, 129-17, https://doi.org/10.6028/jres.026.004 . [all data]

Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E., The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]

Forziati, Norris, et al., 1949, 2
Forziati, A.F.; Norris, W.R.; Rossini, F.D., Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons, J. Res. Natl. Bur. Stand. (U.S.), 1949, 43, 6, 555-563, https://doi.org/10.6028/jres.043.050 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, References

Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
P_c	Critical pressure
S°_gas	Entropy of gas at standard conditions
S°_liquid	Entropy of liquid at standard conditions
T_boil	Boiling point
T_c	Critical temperature
T_fus	Fusion (melting) point
T_triple	Triple point temperature
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fusH	Enthalpy of fusion
Δ_fusS	Entropy of fusion
Δ_vapH	Enthalpy of vaporization
Δ_vapH°	Enthalpy of vaporization at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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