Pyridazine

• Formula: C₄H₄N₂
• Molecular weight: 80.0880
• IUPAC Standard InChI: InChI=1S/C4H4N2/c1-2-4-6-5-3-1/h1-4H Copy

  
• IUPAC Standard InChIKey: PBMFSQRYOILNGV-UHFFFAOYSA-N Copy
• CAS Registry Number: 289-80-5
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Other names: Orthodiazine; 1,2-Diazabenzene; 1,2-Diazine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • Gas phase ion energetics data
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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Phase change data

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

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

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
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)

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₄H₃N₂^- +  =

By formula: C₄H₃N₂^- + H⁺ = C₄H₄N₂

Gas Chromatography

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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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Kovats' RI, non-polar column, isothermal

View large format table.

Van Den Dool and Kratz RI, non-polar column, temperature ramp

View large format table.

References

Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Lecat, 1947
Lecat, M., Some azeotropes of which one constituant is heterocyclic nitrogen, Ann. Soc. Sci. Bruxelles, Ser. 1, 1947, 61, 73. [all data]

Tjebbes, Mollberg, et al., 1962
Tjebbes, Jan; Mollberg, René; Lindberg, Bengt; McKay, James; Theander, Olof; Flood, H., The Heats of Combustion and Formation of the Three Diazines and their Resonance Energies., Acta Chem. Scand., 1962, 16, 916-921, https://doi.org/10.3891/acta.chem.scand.16-0916 . [all data]

Tjebbes, 1962
Tjebbes, J., The heats of combustion and formation of the three diazines and their resonance energies, Acta Chem. Scand., 1962, 16, 916-921. [all data]

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]

Suess, Liu, et al., 2003
Suess, L.; Liu, Y.; Parthasarathy, R.; Dunning, F.B., Dipole-bound negative ions: Collisional destruction and blackbody-radiation-induced photodetachment, J. Chem. Phys., 2003, 119, 24, 12890-12894, https://doi.org/10.1063/1.1628215 . [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]

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. XVII. Photoelectron, UV, mass and electron impact spectra of pyridazine, Int. J. Mass Spectrom. Ion Phys., 1972, 8, 229. [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]

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]

Golovnya, Kuz'menko, et al., 2000
Golovnya, R.V.; Kuz'menko, T.E.; Krikunova, N.I., The influence of alkyl substituents on the chromatographic indicator of self-association of N-containing heterocyclic compounds, Russ. Chem. Bull. (Engl. Transl.), 2000, 49, 2, 321-324, https://doi.org/10.1007/BF02494681 . [all data]

Zhuravleva, 2000
Zhuravleva, I.L., Evaluation of the polarity and boiling points of nitrogen-containing heterocyclic compounds by gas chromatography, Russ. Chem. Bull. (Engl. Transl.), 2000, 49, 2, 325-328, https://doi.org/10.1007/BF02494682 . [all data]

Golovnya, Kuz'menko, et al., 1999
Golovnya, R.V.; Kuz'menko, T.E.; Zhuravleva, I.L., Gas chromatographic indicator of the ability of five- and six-membered heterocyclic nitrogen-containing compounds for self-association in pure liquids, Russ. Chem. Bull. (Engl. Transl.), 1999, 48, 4, 726-729, https://doi.org/10.1007/BF02496256 . [all data]

Peng, Ding, et al., 1988
Peng, C.T.; Ding, S.F.; Hua, R.L.; Yang, Z.C., Prediction of Retention Indexes I. Structure-Retention Index Relationship on Apolar Columns, J. Chromatogr., 1988, 436, 137-172, https://doi.org/10.1016/S0021-9673(00)94575-8 . [all data]

Notes

Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, References

• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  Tboil	Boiling point
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH°	Enthalpy of vaporization at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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