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4-Aminopyridine

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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

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

Quantity Value Units Method Reference Comment
Proton affinity (review)979.7kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity947.8kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
8.8 ± 0.1EIStefanovic and Grutzmacher, 1974LLK
9.27 ± 0.05EIGronneberg and Undheim, 1973LLK
8.4CTSDaisey and Sonnessa, 1972LLK
8.97 ± 0.05EIBasila and Clancy, 1963RDSH
8.77PERamsey and Walker, 1974Vertical value; LLK
8.76PEKobayashi and Nagakura, 1974Vertical value; LLK

De-protonation reactions

C5H5N2- + Hydrogen cation = 4-Aminopyridine

By formula: C5H5N2- + H+ = C5H6N2

Quantity Value Units Method Reference Comment
Deltar1494. ± 9.2kJ/molG+TSTaft and Bordwell, 1988gas phase; B
Quantity Value Units Method Reference Comment
Deltar1464. ± 8.4kJ/molIMRETaft and Bordwell, 1988gas 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]

Stefanovic and Grutzmacher, 1974
Stefanovic, D.; Grutzmacher, H.F., The ionisation potential of some substituted pyridines, Org. Mass Spectrom., 1974, 9, 1052. [all data]

Gronneberg and Undheim, 1973
Gronneberg, T.; Undheim, K., Mass spectrometry of onium compounds - XV. ionization potentials of amino pyridines, Tetrahedron Lett., 1973, 3193. [all data]

Daisey and Sonnessa, 1972
Daisey, J.M.; Sonnessa, A.J., A study of the thermodynamic and spectral properties of molecular complexes of iodine with several aminopyridines, J. Phys. Chem., 1972, 76, 1895. [all data]

Basila and Clancy, 1963
Basila, M.R.; Clancy, D.J., The ionization potentials of monosubstituted pyridines by electron impact, J. Phys. Chem., 1963, 67, 1551. [all data]

Ramsey and Walker, 1974
Ramsey, B.G.; Walker, F.A., A linear relationship between substituted pyridine lone pair vertical ionization potentials and pKa, J. Am. Chem. Soc., 1974, 96, 3314. [all data]

Kobayashi and Nagakura, 1974
Kobayashi, T.; Nagakura, S., Photoelectron spectra of aminopyridines and cyanopyridines, J. Electron Spectrosc. Relat. Phenom., 1974, 4, 207. [all data]

Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G., Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase, Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005 . [all data]


Notes

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