2-Butyne

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

View reactions leading to C4H6+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)9.58 ± 0.02eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)775.8kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity745.1kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
9.59 ± 0.02PEBieri, Burger, et al., 1977LLK
9.562 ± 0.005PECarlier, Dubois, et al., 1975LLK
9.61PEEnsslin, Bock, et al., 1974LLK
9.59PEBrogli, Heilbronner, et al., 1973LLK
9.56EILossing, 1972LLK
9.79PEBieri and Asbrink, 1980Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
CH3+17.6 ± 0.5?EICoats and Anderson, 1957RDSH
C2H3+14.7 ± 0.2?EICoats and Anderson, 1957RDSH
C3H3+11.04CH3EILossing, 1972LLK
C4H2+16.7 ± 0.3?EICoats and Anderson, 1957RDSH
C4H3+15.1 ± 0.2H2+HEICoats and Anderson, 1957RDSH
C4H4+14.0 ± 0.1H2EICoats and Anderson, 1957RDSH
C4H5+12.1 ± 0.1HEICoats and Anderson, 1957RDSH

De-protonation reactions

C4H5- + Hydrogen cation = 2-Butyne

By formula: C4H5- + H+ = C4H6

Quantity Value Units Method Reference Comment
Δr1628. ± 8.8kJ/molG+TSGal, Decouzon, et al., 2001gas phase; Acid: MeC≡CMe; B
Δr1628. ± 14.kJ/molG+TSN/Agas phase; Measured vs pyridine; B
Quantity Value Units Method Reference Comment
Δr1597. ± 8.4kJ/molIMREGal, Decouzon, et al., 2001gas phase; Acid: MeC≡CMe; B
Δr1596. ± 13.kJ/molIMREN/Agas phase; Measured vs pyridine; B

References

Go To: Top, Gas phase ion energetics data, Notes

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

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]

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]

Ensslin, Bock, et al., 1974
Ensslin, W.; Bock, H.; Becker, G., Photoelectron spectra and molecular properties. XXX. π interactions in H3Si- H3C-substituted acetylenes, J. Am. Chem. Soc., 1974, 96, 2757. [all data]

Brogli, Heilbronner, et al., 1973
Brogli, F.; Heilbronner, E.; Hornung, V.; Kloster-Jensen, E., 230. Die photoelektronen-spektren methyl-substituierter Acetylene, Helv. Chim. Acta, 1973, 56, 2171. [all data]

Lossing, 1972
Lossing, F.P., Free radicals by mass spectrometry. XLV. Ionization potentials and heats of formation of C3H3, C3H5, and C4H7 radicals and ions, Can. J. Chem., 1972, 50, 3973. [all data]

Bieri and Asbrink, 1980
Bieri, G.; Asbrink, L., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1980, 20, 149. [all data]

Coats and Anderson, 1957
Coats, F.H.; Anderson, R.C., Thermodynamic data from electron-impact measurements on acetylene and substituted acetylenes, J. Am. Chem. Soc., 1957, 79, 1340. [all data]

Gal, Decouzon, et al., 2001
Gal, J.F.; Decouzon, M.; Maria, P.C.; Gonzalez, A.I.; Mo, O.; Yanez, M.; El Chaouch, S.; Guillemin, J.C., Acidity trends in alpha,beta-unsaturated alkanes, silanes, germanes, and stannanes, J. Am. Chem. Soc., 2001, 123, 26, 6353-6359, https://doi.org/10.1021/ja004079j . [all data]


Notes

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