CH2=C=CH anion


Gas phase ion energetics data

Go To: Top, 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: John E. Bartmess

Electron affinity of neutral species

EAneutral (eV) Method Reference Comment
0.9180 ± 0.0080LPESRobinson, Polak, et al., 1995Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic.
0.893 ± 0.026LPESOakes and Ellison, 1983Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic.
2.34166SIPage and Goode, 1969The Magnetron method, lacking mass analysis, is not considered reliable.

Protonation reactions

C3H3- + Hydrogen cation = Allene

By formula: C3H3- + H+ = C3H4

Quantity Value Units Method Reference Comment
Δr380.0 ± 2.0kcal/molD-EARobinson, Polak, et al., 1995gas phase; Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic.
Δr381.4 ± 3.1kcal/molG+TSRobinson, Polak, et al., 1995gas phase; Relative to MeOH at 375.0; kinetic scheme factors in isomerization
Δr380.6 ± 2.1kcal/molD-EAOakes and Ellison, 1983gas phase; Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic.
Quantity Value Units Method Reference Comment
Δr372.8 ± 3.0kcal/molIMRERobinson, Polak, et al., 1995gas phase; Relative to MeOH at 375.0; kinetic scheme factors in isomerization
Δr372.0 ± 2.2kcal/molH-TSOakes and Ellison, 1983gas phase; Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic.

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.

Robinson, Polak, et al., 1995
Robinson, M.S.; Polak, M.L.; Bierbaum, V.M.; DePuy, C.H.; Lineberger, W.C., Experimental Studies of Allene, Methylacetylene, and the Propargyl Radical: Bond Dissociation Energies, Gas-Phase Acidities, and Ion-Molecule Chemistry, J. Am. Chem. Soc., 1995, 117, 25, 6766, https://doi.org/10.1021/ja00130a017 . [all data]

Oakes and Ellison, 1983
Oakes, J.M.; Ellison, B.G., Photoelectron spectroscopy of the allenyl anion CH2=C=CH-, J. Am. Chem. Soc., 1983, 105, 2969. [all data]

Page and Goode, 1969
Page, F.M.; Goode, G.C., Negative Ions and the Magnetron., Wiley, NY, 1969. [all data]


Notes

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