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1-Propene, 2-methyl-

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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
MM - Michael M. Meot-Ner (Mautner)
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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to C4H8+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)9.22 ± 0.02eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)191.7kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity185.4kcal/molN/AHunter and Lias, 1998HL

Proton affinity at 298K

Proton affinity (kcal/mol) Reference Comment
191.8 ± 1.1Bouchoux and Salpin, 1999T = 300K; Re-evaluated thermokinetic parametric fitting by the authors using reference base GBs and PAs from Hunter and Lias, 1998; MM
191.8 ± 1.1Bouchoux and Salpin, 1999T = 298K; MM
192.4 ± 1.6Cleven, Hoke, et al., 1996PA > butyronitrile, < benzonitrile; MM

Gas basicity at 298K

Gas basicity (review) (kcal/mol) Reference Comment
185.5 ± 0.65Bouchoux and Salpin, 1999T = 300K; Re-evaluated thermokinetic parametric fitting by the authors using reference base GBs and PAs from Hunter and Lias, 1998; MM
185.5 ± 0.65Bouchoux and Salpin, 1999T = 298K; MM

Ionization energy determinations

IE (eV) Method Reference Comment
9.19PITraeger, 1986LBLHLM
9.24 ± 0.05EIHolmes and Lossing, 1983LBLHLM
9.24 ± 0.02PEBieri, Burger, et al., 1977LLK
9.239 ± 0.003PEMasclet, Grosjean, et al., 1973LLK
9.19EILossing, 1972LLK
9.21PEFrost and Sandhu, 1971LLK
9.17PEDewar and Worley, 1969RDSH
9.23 ± 0.02PIWatanabe, Nakayama, et al., 1962RDSH
9.23PIBralsford, Harris, et al., 1960RDSH
9.41PEWiberg, Ellison, et al., 1976Vertical value; LLK
9.39PEKoenig, Balle, et al., 1975Vertical value; LLK
9.45PEKimura, Katsumata, et al., 1975Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
CH3+16.4C3H5EISenSharma and Franklin, 1973LLK
C2H4+12.0 ± 0.25?EIMeisels, Park, et al., 1970RDSH
C3H5+11.33CH3PITraeger, 1984LBLHLM
C3H5+11.8CH3EISenSharma and Franklin, 1973LLK
C3H5+11.45CH3EILossing, 1972LLK
C4H6+11.3 ± 0.1H2EIHolmes, Weese, et al., 1977LLK
C4H7+11.26HPITraeger, 1986LBLHLM
C4H7+11.41HEILossing, 1972LLK

De-protonation reactions

C4H7- + Hydrogen cation = 1-Propene, 2-methyl-

By formula: C4H7- + H+ = C4H8

Quantity Value Units Method Reference Comment
Deltar393.0 ± 1.8kcal/molEndoWenthold, Hu, et al., 1999gas phase; B
Deltar387.0 ± 2.0kcal/molD-EAWenthold, Polak, et al., 1996gas phase; B
Deltar390.3 ± 2.3kcal/molG+TSBartmess and Burnham, 1984gas phase; B
Quantity Value Units Method Reference Comment
Deltar385.6 ± 1.9kcal/molH-TSWenthold, Hu, et al., 1999gas phase; B
Deltar379.6 ± 2.1kcal/molH-TSWenthold, Polak, et al., 1996gas phase; B
Deltar382.9 ± 2.2kcal/molIMREBartmess and Burnham, 1984gas phase; 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]

Bouchoux and Salpin, 1999
Bouchoux, J.; Salpin, J.Y., Re-evaluated gas-phase basicity and proton affinity data from the thermokinetic method, Rapid Com. Mass Spectrom., 1999, 13, 932. [all data]

Cleven, Hoke, et al., 1996
Cleven, C.D.; Hoke, S.H.; Cooks, R.G.; Hrovat, D.A.; Smith, J.M.; Lee, M.S.; Borden, W.T., Effect of Olefin Pyramidalization on the Proton Affinity of Tricyclo[3.3.3.03,7]undec-3(7)-ene as Determined by ab Initio Calculations and Kinetic Method Measurements, J. Am. Chem. Soc., 1996, 118, 10872. [all data]

Traeger, 1986
Traeger, J.C., Heat of formation for the 1-methylallyl cation by photoionization mass spectrometry, J. Phys. Chem., 1986, 90, 4114. [all data]

Holmes and Lossing, 1983
Holmes, J.L.; Lossing, F.P., The need for adequate thermochemical data for the interpretation of fragmentation mechanisms and ion structure assignments, Int. J. Mass Spectrom. Ion Phys., 1983, 47, 133. [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]

Masclet, Grosjean, et al., 1973
Masclet, P.; Grosjean, D.; Mouvier, G., Alkene ionization potentials. Part I. Quantitative determination of alkyl group structural effects, J. Electron Spectrosc. Relat. Phenom., 1973, 2, 225. [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]

Frost and Sandhu, 1971
Frost, D.C.; Sandhu, J.S., Ionization potentials of ethylene and some methyl-substituted ethylenes as determined by photoelectron spectroscopy, Indian J. Chem., 1971, 9, 1105. [all data]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation, J. Chem. Phys., 1969, 50, 654. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Bralsford, Harris, et al., 1960
Bralsford, R.; Harris, P.V.; Price, W.C., The effect of fluorine on the electronic spectra and ionization potentials of molecules, Proc. Roy. Soc. (London), 1960, A258, 459. [all data]

Wiberg, Ellison, et al., 1976
Wiberg, K.B.; Ellison, G.B.; Wendoloski, J.J.; Brundle, C.R.; Kuebler, N.A., Electronic states of organic molecules. 3. Photoelectron spectra of cycloalkenes and methylenecycloalkanes, J. Am. Chem. Soc., 1976, 98, 7179. [all data]

Koenig, Balle, et al., 1975
Koenig, T.; Balle, T.; Snell, W., Helium(I) photoelectron spectra of organic radicals, J. Am. Chem. Soc., 1975, 97, 662. [all data]

Kimura, Katsumata, et al., 1975
Kimura, K.; Katsumata, S.; Yamazaki, T.; Wakabayashi, H., UV photoelectron spectra and sum rule consideration; out-of-plane orbitals of unsaturated compounds with planar-skeleton structure, J. Electron Spectrosc. Relat. Phenom., 1975, 6, 41. [all data]

SenSharma and Franklin, 1973
SenSharma, D.K.; Franklin, J.L., Heat of formation of free radicals by mass spectrometry, J. Am. Chem. Soc., 1973, 95, 6562. [all data]

Meisels, Park, et al., 1970
Meisels, G.G.; Park, J.Y.; Giessner, B.G., Ionization and dissociation of C4H8 isomers, J. Am. Chem. Soc., 1970, 92, 254. [all data]

Traeger, 1984
Traeger, J.C., A study of the allyl cation thermochemistry by photoionization mass spectrometry, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 259. [all data]

Holmes, Weese, et al., 1977
Holmes, J.L.; Weese, G.M.; Blair, A.S.; Terlouw, J.K., Metastable ion studies IX-Thermochemistry and ion structures among fragmenting [C4H8]+ ions, an electron impact and field ionization investigation, Org. Mass Spectrom., 1977, 12, 424. [all data]

Wenthold, Hu, et al., 1999
Wenthold, P.G.; Hu, J.; Squires, R.R.; Lineberger, W.C., Photoelectron spectroscopy of the trimethylenemethane negative ion, J. Am. Soc. Mass Spectrom., 1999, 10, 9, 800-809, https://doi.org/10.1016/S1044-0305(99)00043-4 . [all data]

Wenthold, Polak, et al., 1996
Wenthold, P.G.; Polak, M.L.; Lineberger, W.C., Photoelectron Spectroscopy of the Allyl and 2-Methylallyl Anions, J. Phys. Chem., 1996, 100, 17, 6920, https://doi.org/10.1021/jp953401n . [all data]

Bartmess and Burnham, 1984
Bartmess, J.E.; Burnham, R., Effect of central substituents on the gas phase acidities of propenes, J. Org. Chem., 1984, 49, 1382. [all data]


Notes

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