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1,3-Diazine

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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
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 C4H4N2+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)9.33 ± 0.07eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)885.8kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity855.7kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
>-0.24999ETSNenner and Schultz, 1975Pyrimidine. EA estimated as 0 eV, based on soln phase electrochemical correlations. G3MP2B3 calculations put EA at -4 kcal/mol; B

Ionization energy determinations

IE (eV) Method Reference Comment
9.1PEPiancastelli, Keller, et al., 1983LBLHLM
9.23PEGleiter, Heilbronner, et al., 1972LLK
9.32 ± 0.01PEAsbrink, Fridh, et al., 1972LLK
9.42PEDewar and Worley, 1969RDSH
9.35 ± 0.01PIYencha and El-Sayed, 1968RDSH
9.73 ± 0.03PEHush and Cheung, 1975Vertical value; LLK
9.73PESuffolk, 1974Vertical value; LLK
9.73PEGleiter, Heilbronner, et al., 1970Vertical value; RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C3H2N+15.01 ± 0.10?EIMomigny, Urbain, et al., 1965RDSH
C3H3N+12.87 ± 0.10HCNEIMomigny, Urbain, et al., 1965RDSH
C4H3N2+13.01 ± 0.10HEIMomigny, Urbain, et al., 1965RDSH

De-protonation reactions

C4H3N2- + Hydrogen cation = 1,3-Diazine

By formula: C4H3N2- + H+ = C4H4N2

Quantity Value Units Method Reference Comment
Deltar1612. ± 10.kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Acid: pyrimidine. Anchored to 88MEO scale, not "87 acidity scale; B
Quantity Value Units Method Reference Comment
Deltar1576.5 ± 2.9kJ/molN/AWren, Vogelhuber, et al., 2012gas phase; B
Deltar1577. ± 8.4kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Acid: pyrimidine. Anchored to 88MEO scale, not "87 acidity scale; 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]

Nenner and Schultz, 1975
Nenner, I.; Schultz, G.J., Temporary negative ions and electron affinities of benzene and N-heterocyclic molecules: Pyridine, pyridazine, pyrimidine, pyrazine, and s-triazine, J. Chem. Phys., 1975, 62, 1747. [all data]

Piancastelli, Keller, et al., 1983
Piancastelli, M.N.; Keller, P.R.; Taylor, J.W.; Grimm, F.A.; Carlson, T.A., Angular distribution parameter as a function of photon energy for some mono- and diazabenzenes and its use for orbital assignment, J. Am. Chem. Soc., 1983, 105, 4235. [all data]

Gleiter, Heilbronner, et al., 1972
Gleiter, R.; Heilbronner, E.; Hornung, V., Photoelectron spectra of azabenzenes azanaphthalenes: I. Pyridine, diazines s-triazine and s-tetrazine, Helv. Chim. Acta, 1972, 55, 255. [all data]

Asbrink, Fridh, et al., 1972
Asbrink, L.; Fridh, C.; Jonsson, B.O.; Lindholm, E., Rydberg series in small molecules. XVI. Photoelectron, UV, mass and electron impact spectra of pyrimidine, Int. J. Mass Spectrom. Ion Phys., 1972, 8, 215. [all data]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. II.The ionization potentials of azabenzenes and azanaphthalenes, J. Chem. Phys., 1969, 51, 263. [all data]

Yencha and El-Sayed, 1968
Yencha, A.J.; El-Sayed, M.A., Lowest ionization potentials of some nitrogen heterocyclics, J. Chem. Phys., 1968, 48, 3469. [all data]

Hush and Cheung, 1975
Hush, N.S.; Cheung, A.S., Ionization potentials and donor properties of nucleic acid bases and related compounds, Chem. Phys. Lett., 1975, 34, 11. [all data]

Suffolk, 1974
Suffolk, R.J., The photoelectron spectra of the perfluorodiazines, J. Electron Spectrosc. Relat. Phenom., 1974, 3, 53. [all data]

Gleiter, Heilbronner, et al., 1970
Gleiter, R.; Heilbronner, E.; Hornung, V., Lone pair interaction in pyridazine, pyrimidine, and pyrazine, Angew. Chem. Int. Ed. Engl., 1970, 9, 901. [all data]

Momigny, Urbain, et al., 1965
Momigny, J.; Urbain, J.; Wankenne, H., Les effets de l'impact electronique sur la pyridine et les diazines isomeres, Bull. Soc. Roy. Sci. Liege, 1965, 34, 337. [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]

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]


Notes

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