Heptane, 2-methyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: JVSWJIKNEAIKJW-UHFFFAOYSA-N
- CAS Registry Number: 592-27-8
- 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. - Isotopologues:
- Other names: 2-Methylheptane; (CH3)2CH(CH2)4CH3; Methylheptane
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Gas phase thermochemistry data
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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
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -51.50 ± 0.31 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 109.82 ± 0.21 | cal/mol*K | N/A | Messerly J.F., 1971 | GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
44.486 | 298.15 | Colgate S.O., 1990 | GT |
48.296 | 323.15 | ||
54.986 | 373.15 | ||
59.362 | 408.15 | ||
63.461 | 448.15 |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
32.421 | 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 |
41.561 | 273.15 | ||
44.75 ± 0.05 | 298.15 | ||
44.981 | 300. | ||
57.660 | 400. | ||
69.020 | 500. | ||
78.700 | 600. | ||
86.800 | 700. | ||
93.599 | 800. | ||
99.500 | 900. | ||
104.40 | 1000. | ||
108.70 | 1100. | ||
112.50 | 1200. | ||
116.00 | 1300. | ||
119.00 | 1400. | ||
122.00 | 1500. |
Gas phase ion energetics data
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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:
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 9.84 ± 0.10 | eV | N/A | N/A | L |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.76 | EST | Luo and Pacey, 1992 | LL |
9.84 ± 0.10 | EVAL | Lias, 1982 | LBLHLM |
9.74 ± 0.15 | EQ | Mautner(Meot-Ner), Sieck, et al., 1981 | LLK |
IR Spectrum
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Gas Phase Spectrum
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Additional Data
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Owner | NIST Standard Reference Data Program Collection (C) 2018 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center |
State | gas |
Instrument | HP-GC/MS/IRD |
References
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, IR Spectrum, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D.,
Heats of combustion and formation of the paraffin hydrocarbons at 25° C,
J. Res. NBS, 1945, 263-267. [all data]
Messerly J.F., 1971
Messerly J.F.,
Low-temperature thermal properties of 2-methylheptane and 2-methyldecane: the thermodynamic properties of 2-methylalkanes,
J. Chem. Thermodyn., 1971, 3, 675-687. [all data]
Colgate S.O., 1990
Colgate S.O.,
Acoustical determination of ideal gas heat capacities of three C-8 compounds,
Fluid Phase Equilib., 1990, 60, 191-203. [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]
Luo and Pacey, 1992
Luo, Y.-R.; Pacey, P.D.,
Effects of alkyl substitution on ionization energies of alkanes and haloalkanes and on heats of formation of their molecular cations. Part 2. Alkanes and chloro-, bromo- and iodoalkanes,
Int. J. Mass Spectrom. Ion Processes, 1992, 112, 63. [all data]
Lias, 1982
Lias, S.G.,
Thermochemical information from ion-molecule rate constants,
Ion Cyclotron Reson. Spectrom. 1982, 1982, 409. [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]
Notes
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- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas IE (evaluated) Recommended ionization energy S°gas Entropy of gas at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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