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Pyridazine

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Gas phase thermochemistry 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 compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Deltafgas278.4 ± 1.3kJ/molCcbTjebbes, 1962 

Condensed phase thermochemistry 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 compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Deltafliquid224.9 ± 0.92kJ/molCcbTjebbes, 1962 
Quantity Value Units Method Reference Comment
Deltacliquid-2370.6 ± 0.92kJ/molCcbTjebbes, 1962 

Phase change 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 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.

Quantity Value Units Method Reference Comment
Tboil481.2KN/AWeast and Grasselli, 1989BS
Tboil480.35KN/ALecat, 1947Uncertainty assigned by TRC = 0.6 K; TRC
Quantity Value Units Method Reference Comment
Deltavap53.5 ± 0.4kJ/molCTjebbes, Mollberg, et al., 1962AC
Deltavap53.5 ± 0.4kJ/molCTjebbes, 1962ALS
Deltavap53.5kJ/molN/ATjebbes, 1962DRB

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


Reaction thermochemistry 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 compiled by: John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

C4H3N2- + Hydrogen cation = Pyridazine

By formula: C4H3N2- + H+ = C4H4N2

Quantity Value Units Method Reference Comment
Deltar1600. ± 10.kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Pyridazine. Anchored to 88MEO scale, not the "87 Acidity Scale".
Quantity Value Units Method Reference Comment
Deltar1564.8 ± 2.9kJ/molN/AWren, Vogelhuber, et al., 2012gas phase
Deltar1562. ± 8.4kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Pyridazine. Anchored to 88MEO scale, not the "87 Acidity Scale".

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)

Quantity Value Units Method Reference Comment
IE (evaluated)8.74 ± 0.11eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)907.2kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity877.1kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.01201EFDSuess, Liu, et al., 2003B
>-0.31699ETSNenner and Schultz, 1975Pyridazine. EA estimated as 0.25 eV based on solution phase electrochemical correlations; B

Ionization energy determinations

IE (eV) Method Reference Comment
8.64PEGleiter, Heilbronner, et al., 1972LLK
8.706 ± 0.001PEAsbrink, Fridh, et al., 1972LLK
8.90PEDewar and Worley, 1969RDSH
8.71 ± 0.01PIYencha and El-Sayed, 1968RDSH
9.31PESuffolk, 1974Vertical value; LLK
9.31PEGleiter, Heilbronner, et al., 1970Vertical value; RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C2H2+14.94 ± 0.10?EIMomigny, Urbain, et al., 1965RDSH
C2H2+15.79 ± 0.05?EIMomigny, Urbain, et al., 1965RDSH
C2H2+15.23 ± 0.10?EIMomigny, Urbain, et al., 1965RDSH
C4H2+13.67 ± 0.10N2+H2EIMomigny, Urbain, et al., 1965RDSH
C4H3+13.84 ± 0.10N2+HEIMomigny, Urbain, et al., 1965RDSH
C4H4+11.64 ± 0.05N2EIMomigny, Urbain, et al., 1965RDSH

De-protonation reactions

C4H3N2- + Hydrogen cation = Pyridazine

By formula: C4H3N2- + H+ = C4H4N2

Quantity Value Units Method Reference Comment
Deltar1600. ± 10.kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Pyridazine. Anchored to 88MEO scale, not the "87 Acidity Scale".; B
Quantity Value Units Method Reference Comment
Deltar1564.8 ± 2.9kJ/molN/AWren, Vogelhuber, et al., 2012gas phase; B
Deltar1562. ± 8.4kJ/molTDEqMeot-ner and Kafafi, 1988gas phase; Pyridazine. Anchored to 88MEO scale, not the "87 Acidity Scale".; B

IR Spectrum

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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: Coblentz Society, Inc.

Condensed Phase Spectrum

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IR spectrum
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Notice: Except where noted, spectra from this collection were measured on dispersive instruments, often in carefully selected solvents, and hence may differ in detail from measurements on FTIR instruments or in other chemical environments. More information on the manner in which spectra in this collection were collected can be found here.

Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.

Additional Data

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Owner COPYRIGHT (C) 1988 by COBLENTZ SOCIETY INC.
Collection (C) 2018 copyright by the U.S. Secretary of Commerce
on behalf of the United States of America. All rights reserved.
Origin DOW CHEMICAL COMPANY
Source reference COBLENTZ NO. 06364
Date 1965/11/10
State LIQUID (NEAT)
Instrument BECKMAN IR-9 (GRATING)
Instrument parameters ORDER CHANGES: 670, 1200, 2000 CM-1
Path length CAPILLARY
SPECTRAL CONTAMINATION DUE TO H2O AROUND 1670, 3450 AND AN UNKNOWN AROUND 400 CM-1
Resolution 2
Sampling procedure TRANSMISSION
Data processing DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY

This IR spectrum is from the Coblentz Society's evaluated infrared reference spectra collection.


Mass spectrum (electron ionization)

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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

Spectrum

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Mass spectrum
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Additional Data

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Owner NIST Mass Spectrometry Data Center
Collection (C) 2014 copyright by the U.S. Secretary of Commerce
on behalf of the United States of America. All rights reserved.
Origin Japan AIST/NIMC Database- Spectrum MS-NW-5023
NIST MS number 230162

All mass spectra in this site (plus many more) are available from the NIST/EPA/NIH Mass Spectral Library. Please see the following for information about the library and its accompanying search program.


UV/Visible spectrum

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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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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UVVis spectrum
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Additional Data

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Source Halverson and Hirt, 1951
Owner INEP CP RAS, NIST OSRD
Collection (C) 2007 copyright by the U.S. Secretary of Commerce
on behalf of the United States of America. All rights reserved.
Origin INSTITUTE OF ENERGY PROBLEMS OF CHEMICAL PHYSICS, RAS
Source reference RAS UV No. 12007
Instrument Beckman DU
Melting point - 8
Boiling point 208

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Notes

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

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]

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]

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]

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]

Halverson and Hirt, 1951
Halverson, F.; Hirt, R.C., J. Chem. Phys., 1951, 19, 711. [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, References