1-Butyne, 3-methyl-

• Formula: C₅H₈
• Molecular weight: 68.1170
• IUPAC Standard InChI: InChI=1S/C5H8/c1-4-5(2)3/h1,5H,2-3H3 Copy

  
• IUPAC Standard InChIKey: USCSRAJGJYMJFZ-UHFFFAOYSA-N Copy
• CAS Registry Number: 598-23-2
• 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.
• Species with the same structure:
  • 1-Butyne, 3-methyl
• Other names: Isopentyne; Isopropyl acetylene; 2-Methyl-3-butyne; 3-Methyl-1-butyne; 3-Methylbutyne; (CH3)2CHC≡CH; 3-methylbut-1-yne
• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • IR Spectrum
  • References
  • Notes
• Other data available:
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
• Options:
  • Switch to SI units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Phase change data, Gas phase ion energetics data, IR Spectrum, References, Notes

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

Phase change data

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

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

Enthalpy of vaporization

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, IR Spectrum, References, Notes

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:
HL - Edward P. Hunter and Sharon G. Lias

Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

View reactions leading to C₅H₈⁺ (ion structure unspecified)

Ionization energy determinations

IR Spectrum

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

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

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.

Additional Data

References

Go To: Top, Gas phase thermochemistry data, Phase change 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.

Wagman, Kilpatrick, et al., 1945
Wagman, D.D.; Kilpatrick, J.E.; Pitzer, K.S.; Rossini, F.D., Heats, equilibrium constants, and free energies of formation of the acetylene hydrocarbons through the pentynes, to 1,500° K, J. Res. NBS, 1945, 35, 467-496. [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]

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]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Holmes, Fingas, et al., 1981
Holmes, J.L.; Fingas, M.; Lossing, F.P., Towards a general scheme for estimating the heats of formation of organic ions in the gas phase. Part I. Odd-electron cations, Can. J. Chem., 1981, 59, 80. [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]

Carlier, Dubois, et al., 1975
Carlier, P.; Dubois, J.E.; Masclet, P.; Mouvier, G., Spectres de photoelectrons des alcynes, J. Electron Spectrosc. Relat. Phenom., 1975, 7, 55. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, References

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  Tboil	Boiling point
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔvapH	Enthalpy of vaporization

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.