CH2=C=CH anion
- Formula: C3H3-
- Molecular weight: 39.0565
- CAS Registry Number: 64066-06-4
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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 compiled by: John E. Bartmess
Electron affinity of neutral species
| EAneutral (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.9180 ± 0.0080 | LPES | Robinson, Polak, et al., 1995 | Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic. |
| 0.893 ± 0.026 | LPES | Oakes and Ellison, 1983 | Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic. |
| 2.34166 | SI | Page and Goode, 1969 | The Magnetron method, lacking mass analysis, is not considered reliable. |
Protonation reactions
C3H3- + =
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 380.0 ± 2.0 | kcal/mol | D-EA | Robinson, Polak, et al., 1995 | gas phase; Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic. |
| ΔrH° | 381.4 ± 3.1 | kcal/mol | G+TS | Robinson, Polak, et al., 1995 | gas phase; Relative to MeOH at 375.0; kinetic scheme factors in isomerization |
| ΔrH° | 380.6 ± 2.1 | kcal/mol | D-EA | Oakes and Ellison, 1983 | gas phase; Neutral acid: allene. Propyne would be 1.0 kcal/mol less acidic. |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 372.8 ± 3.0 | kcal/mol | IMRE | Robinson, Polak, et al., 1995 | gas phase; Relative to MeOH at 375.0; kinetic scheme factors in isomerization |
| ΔrG° | 372.0 ± 2.2 | kcal/mol | H-TS | Oakes and Ellison, 1983 | gas 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
- Symbols used in this document:
EAneutral Electron affinity of neutral species ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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