1,3-Diazine

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.


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 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)211.7kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity204.5kcal/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
Δr385.2 ± 2.5kcal/molTDEqMeot-ner and Kafafi, 1988gas phase; Acid: pyrimidine. Anchored to 88MEO scale, not "87 acidity scale; B
Quantity Value Units Method Reference Comment
Δr376.80 ± 0.70kcal/molN/AWren, Vogelhuber, et al., 2012gas phase; B
Δr376.9 ± 2.0kcal/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

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