p-pyridinide anion
- Formula: C5H4N-
- Molecular weight: 78.0925
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Reaction thermochemistry data
Go To: Top, 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: John E. Bartmess
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Individual Reactions
By formula: C5H4N- + H+ = C5H5N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 389.9 ± 2.0 | kcal/mol | IMRE | Schafman and Wenthold, 2007 | gas phase |
ΔrH° | 391.0 ± 2.5 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho. |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 382.7 ± 2.0 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho. |
ΔrG° | 384.0 ± 3.0 | kcal/mol | IMRB | DePuy, Kass, et al., 1988 | gas phase; Comparable to water in acidity |
ΔrG° | <376.3 ± 2.0 | kcal/mol | IMRB | Bruins, Ferrer-Correia, et al., 1978 | gas phase; O- deprotonates |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry 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: John E. Bartmess
Electron affinity of neutral species
EAneutral (eV) | Method | Reference | Comment |
---|---|---|---|
1.480 ± 0.020 | N/A | Culberson, Blackstone, et al., 2013 | |
1.4800 ± 0.0060 | LPES | Wren, Vogelhuber, et al., 2012 | |
1.59 ± 0.19 | D-EA | Schafman and Wenthold, 2007 | |
1.54 ± 0.20 | D-EA | Meot-ner and Kafafi, 1988 | anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho. |
2.411 ± 0.030 | SI | Failes, Joyce, et al., 1976 | The Magnetron method, lacking mass analysis, is not considered reliable. |
Protonation reactions
By formula: C5H4N- + H+ = C5H5N
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 389.9 ± 2.0 | kcal/mol | IMRE | Schafman and Wenthold, 2007 | gas phase |
ΔrH° | 391.0 ± 2.5 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho. |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 382.7 ± 2.0 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho. |
ΔrG° | 384.0 ± 3.0 | kcal/mol | IMRB | DePuy, Kass, et al., 1988 | gas phase; Comparable to water in acidity |
ΔrG° | <376.3 ± 2.0 | kcal/mol | IMRB | Bruins, Ferrer-Correia, et al., 1978 | gas phase; O- deprotonates |
References
Go To: Top, Reaction thermochemistry data, 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.
Schafman and Wenthold, 2007
Schafman, B.S.; Wenthold, P.G.,
Regioselectivity of pyridine deprotonation in the gas phase,
J. Org. Chem., 2007, 72, 5, 1645-1651, https://doi.org/10.1021/jo062117x
. [all data]
Meot-ner and Kafafi, 1988
Meot-ner, M.; Kafafi, S.A.,
Carbon Acidities of Aromatic Compounds,
J. Am. Chem. Soc., 1988, 110, 19, 6297, https://doi.org/10.1021/ja00227a003
. [all data]
Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B.,
Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine,
J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z
. [all data]
DePuy, Kass, et al., 1988
DePuy, C.H.; Kass, S.R.; Bean, G.P.,
Formation and Reactions of Heteroaromatic Anions in the Gas Phase,
J. Org. Chem., 1988, 53, 19, 4427, https://doi.org/10.1021/jo00254a001
. [all data]
Bruins, Ferrer-Correia, et al., 1978
Bruins, A.P.; Ferrer-Correia, A.J.; Harrison, A.G.; Jennings, K.R.; Mithcum, R.K.,
Negative ion chemical ionization mass spectrometry of some aromatic compounds using O-. as the reagent ion,
Adv. Mass Spectrom., 1978, 7, 355. [all data]
Culberson, Blackstone, et al., 2013
Culberson, L.M.; Blackstone, C.C.; Sanov, A.,
Photoelectron Angular Distributions of Pyridinide: A Benchmark Application of the Mixed s-p Model to a Truly Polyatomic Anion,
J. Phys. Chem. A, 2013, 117, 46, 11760-11765, https://doi.org/10.1021/jp402507v
. [all data]
Wren, Vogelhuber, et al., 2012
Wren, S.W.; Vogelhuber, K.M.; Garver, J.M.; Kato, S.; Sheps, L.; Bierbaum, V.M.; Lineberger, W.C.,
C-H Bond Strengths and Acidities in Aromatic Systems: Effects of Nitrogen Incorporation in Mono-, Di-, and Triazines,
J. Am. Chem. Soc., 2012, 134, 15, 6584-6595, https://doi.org/10.1021/ja209566q
. [all data]
Failes, Joyce, et al., 1976
Failes, R.L.; Joyce, J.T.; Walton, E.C.,
The behaviour of some dimethyl and trimethyl substituted pyridines in the magnetron,
J. Phys. D: Appl. Phys., 1976, 9, 1543. [all data]
Notes
Go To: Top, Reaction thermochemistry data, 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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