Neopentane

• Formula: C₅H₁₂
• Molecular weight: 72.1488
• IUPAC Standard InChI: InChI=1S/C5H12/c1-5(2,3)4/h1-4H3 Copy

  
• IUPAC Standard InChIKey: CRSOQBOWXPBRES-UHFFFAOYSA-N Copy
• CAS Registry Number: 463-82-1
• 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: Propane, 2,2-dimethyl-; tert-Pentane; Tetramethylcarbon; Tetramethylmethane; 1,1,1-Trimethylethane; 2,2-Dimethylpropane; Neo-C5H12; UN 2044; Dimethylpropane
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • IR Spectrum
  • Gas Chromatography
  • Fluid Properties
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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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

Constant pressure heat capacity of gas

Constant pressure heat capacity of gas

Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Phase change 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:
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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis

Enthalpy of vaporization

Enthalpy of vaporization

Δ_vapH = A exp(-βT_r) (1 − T_r)^β
    Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kJ/mol)
    T_r = reduced temperature (T / T_c)

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Entropy of vaporization

Antoine Equation Parameters

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

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Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

Henry's Law 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 by: Rolf Sander

Henry's Law constant (water solution)

k_H(T) = k°_H exp(d(ln(k_H))/d(1/T) ((1/T) - 1/(298.15 K)))
k°_H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(k_H))/d(1/T) = Temperature dependence constant (K)

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:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₅H₁₁^- +  =

By formula: C₅H₁₁^- + H⁺ = C₅H₁₂

Mass spectrum (electron ionization)

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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

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Good, 1970
Good, W.D., The enthalpies of combustion and formation of the isomeric pentanes, J. Chem. Thermodyn., 1970, 2, 237-244. [all data]

Pilcher and Chadwick, 1967
Pilcher, G.; Chadwick, J.D.M., Measurements of heats of combustion by flame calorimetry. Part 4.-n-Pentane, isopentane, neopentane, Trans. Faraday Soc., 1967, 63, 2357-2361. [all data]

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]

Hossenlopp I.A., 1981
Hossenlopp I.A., Vapor heat capacities and enthalpies of vaporization of five alkane hydrocarbons, J. Chem. Thermodyn., 1981, 13, 415-421. [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]

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Pedley, J.B.; Naylor, R.D.; Kirby, S.P., Thermochemical Data of Organic Compounds, Chapman and Hall, New York, 1986, 1-792. [all data]

Enokida, Shinoda, et al., 1969
Enokida, H.; Shinoda, T.; Mashiko, Y., Thermodynamic properties of neopentane from 4K to the melting point and comparison with spectroscopic data, Bull. Chem. Soc. Japan, 1969, 42, 84-91. [all data]

Aston and Messerly, 1936
Aston, J.G.; Messerly, G.H., Heat capacities and entropies of organic compounds. II. Thermal and vapor pressure data for tetramethylmethane from 13.22°K to the boiling point. The entropy from its Raman spectrum, J. Am. Chem. Soc., 1936, 58, 2354-2361. [all data]

Enokido, Shinoda, et al., 1969
Enokido, H.; Shinoda, T.; Mashiko, Y.-I., Thermodynamic Properties of Neopentane from 4 K to the Melting Point and Comparison with Spectroscopic Data, Bull. Chem. Soc. Jpn., 1969, 42, 84. [all data]

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Aston and Messerly, 1936, 2
Aston, J.G.; Messerly, G.H., Heat Capacities and Entropies of Organic Compounds II. Thermal and Vapor Pressure Data for Tetramethylmethane from 13.22K to the Boiling Point. The Entropy from its Raman Spectrum, J. Am. Chem. Soc., 1936, 58, 2354. [all data]

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Dawson, Silberberg, et al., 1973
Dawson, Perry P.; Silberberg, I. Harold; McKetta, John J., Volumetric behavior, vapor pressures, and critical properties of neopentane, J. Chem. Eng. Data, 1973, 18, 1, 7-15, https://doi.org/10.1021/je60056a007 . [all data]

Partington, Rowlinson, et al., 1960
Partington, E.J.; Rowlinson, J.S.; Weston, J.F., The Gas-Liquid Critical Temperatures of Binary Mixtures. Part 1., Trans. Faraday Soc., 1960, 56, 479. [all data]

Beattie, Douslin, et al., 1951
Beattie, J.A.; Douslin, D.R.; Levine, S.W., The vapor pressure and critical constants of neopentane., J. Chem. Phys., 1951, 19, 948. [all data]

Hossenlopp and Scott, 1981
Hossenlopp, I.A.; Scott, D.W., Vapor heat capacities and enthalpies of vaporization of five alkane hydrocarbons, J. Chem. Thermodyn., 1981, 13, 415-421. [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]

Höpfner, Parekh, et al., 2010
Höpfner, A.; Parekh, N.; Hörner, Ch.; Abdel-Hamid, A., Der Dampfdruck-Isotopie-Effekt von deuterierten Neopentanen, Berichte der Bunsengesellschaft für physikalische Chemie, 2010, 79, 2, 216-222, https://doi.org/10.1002/bbpc.19750790217 . [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]

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]

Das, Reed, et al., 1977
Das, Tarun R.; Reed, Charles O.; Eubank, Philip T., PVT surface and thermodynamic properties of isopentane, J. Chem. Eng. Data, 1977, 22, 1, 9-15, https://doi.org/10.1021/je60072a015 . [all data]

Hopfner, Parekh, et al., 1975
Hopfner, A.; Parekh, N.; Horner, Ch.; Abdel-Hamid, A., Der Dampfdruck-Isotopie-Effekt von deuterierten Neopentanen, Ber. Bunsen-Ges. Phys. Chem., 1975, 79, 2, 216-222, https://doi.org/10.1002/bbpc.19750790217 . [all data]

Osborn and Douslin, 1974
Osborn, Ann G.; Douslin, Donald R., Vapor-pressure relations for 15 hydrocarbons, J. Chem. Eng. Data, 1974, 19, 2, 114-117, https://doi.org/10.1021/je60061a022 . [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

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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]

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Chang, E.T.; Westrum, E.F., Heat capacities and thermodynamic properties of globular molecules. XV. The binary system tetramethylmethane-tetrachloromethane, J. Phys. Chem., 1970, 74, 2528-2538. [all data]

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Jonas, A.E.; Schweitzer, G.K.; Grimm, F.A.; Carlson, T.A., The photoelectron spectra of the tetrafluoro and tetramethyl compounds of the group IV elements, J. Electron Spectrosc. Relat. Phenom., 1973, 1, 29. [all data]

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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]

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Schmidt, W.; Wilkins, B.T., Das "Equivalent Orbital" (EO)-verfahren zur interpretation von photoelektronen(PE)-spektren: Neopentan, Angew. Chem., 1972, 84, 168. [all data]

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Murrell, J.N.; Schmidt, W., Photoelectron spectroscopic correlation of the molecular orbitals of methane, ethane, propane, isobutane and neopentane, J. Chem. Soc. Faraday Trans. 2, 1972, 68, 1709. [all data]

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Lampe, F.W.; Field, F.H., The decomposition of neopentane under electron impact, J. Am. Chem. Soc., 1959, 81, 3238. [all data]

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Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔcH°gas	Enthalpy of combustion of gas at standard conditions
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ΔvapS	Entropy of vaporization
  ρc	Critical density

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