1H-1,2,4-Triazole

• Formula: C₂H₃N₃
• Molecular weight: 69.0653
• IUPAC Standard InChI: InChI=1S/C2H3N3/c1-3-2-5-4-1/h1-2H,(H,3,4,5) Copy

  
• IUPAC Standard InChIKey: NSPMIYGKQJPBQR-UHFFFAOYSA-N Copy
• CAS Registry Number: 288-88-0
• 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.
• Species with the same structure:
  • 4H-1,2,4-triazole
• Other names: s-Triazole; 1,2,4-Triazole; 1,2,4-1H-Triazole; CGA-71019; Pyrrodiazole
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Ion clustering data
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Options:
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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, 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.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of fusion

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, 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

Data compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

Ionization energy determinations

De-protonation reactions

C₂H₂N₃^- +  =

By formula: C₂H₂N₃^- + H⁺ = C₂H₃N₃

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, 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.

Jimenez, Roux, et al., 1989
Jimenez, P.; Roux, M.V.; Turrion, C., Thermochemical properties of N-heterocyclic compounds II. Enthalpies of combustion, vapour pressures, enthalpies of sublimation, and enthalpies of formation of 1,2,4-triazole and benzotriazole, J. Chem. Thermodyn., 1989, 21, 759-764. [all data]

Faour and Akasheh, 1985
Faour, M.; Akasheh, T.S., Heat of combustion of some N-heterocycle compounds. Part 1, J. Chem. Soc. Perkin Trans. 2, 1985, 811-713. [all data]

Masalitinova, Oleinikova, et al., 1984
Masalitinova, T.N.; Oleinikova, T.P.; Polyakova, L.P., Thermochemical study of 1,2,4-triazole as a reference substnace for the calorimetry of combustion of organonitrogen compounds, Ref. Zh., Khim.; Abstr. No. 7B3028, 1984, 0. [all data]

Aleksandrov, Osipova, et al., 1982
Aleksandrov, Yu.I.; Osipova, T.R.; Yuhkevich, V.F., Study of 1,2,4-triazole as a standard sample in the calorimetry of thoroughly nitrided organic compounds, Termodin. Organ. Soedin., 1982, 42-45. [all data]

Zimmerman and Geisenfelder, 1961
Zimmerman, H.; Geisenfelder, H., Uber die Mesomerieenergie von Azolen, Z. Electrochem., 1961, 65, 368-371. [all data]

Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc., Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]

Bruhl, 1895
Bruhl, J.W., Spectrochemistry of Nitrogen-Containing Compounds. I., Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1895, 16, 193. [all data]

Hilgeman, Mouroux, et al., 1989
Hilgeman, F.R.; Mouroux, F.Y.N.; Mok, D.; Holan, M.K., Phase Diagrams of Binary Solid Azole Systems, J. Chem. Eng. Data, 1989, 34, 220. [all data]

Vorontsova and Vlasov, 1987
Vorontsova, N.A.; Vlasov, O.N., Determination of saturated vapor pressure of Bayletone and its semiproducts, Deposited Doc. ONIITEkhim Cherkassy, 1987, Doc. No. 1423 khp - 87, 1987. [all data]

Hilgeman, Mouroux, et al., 1989, 2
Hilgeman, F.R.; Mouroux, F.Y.N.; Mok, D.; Holan, M.K., Phase diagrams of binary solid azole systems, J. Chem. Eng. Data, 1989, 34, 220-222. [all data]

Sabbah and Perez, 1999
Sabbah, Raphaël; Perez, Laurence, Energetics of Intramolecular Bonds in 1H-1,2,4-Triazole and 1H-Benzotriazole, Aust. J. Chem., 1999, 52, 4, 235-621, https://doi.org/10.1071/C99006 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [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]

Palmer, Simpson, et al., 1981
Palmer, M.H.; Simpson, I.; Wheeler, J.R., Gas phase tautomerism in the triazoles and tetrazoles: A study by photoelectron spectroscopy and ab initio molecular orbital calculations, Z. Naturforsch. A:, 1981, 36, 1246. [all data]

Guimon, Pfister-Guillouzo, et al., 1980
Guimon, C.; Pfister-Guillouzo, G.; Bernardini, A.; Viallefont, P., A photoelectron study (HeI, HeII) of the tautomeric equilibrium of chloro- and bromo-1,2,4-triazoles, Tetrahedron, 1980, 36, 1071. [all data]

Cradock, Findlay, et al., 1973
Cradock, S.; Findlay, R.H.; Palmer, M.H., The molecular energy levels of the azoles: A study by photoelectron spectroscopy and ab initio molecular orbital calculations, Tetrahedron, 1973, 29, 2173. [all data]

Taft, 1991
Taft, R.W., , personal communication, Aug, 1991. [all data]

Notes

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

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  Tboil	Boiling point
  Tfus	Fusion (melting) point
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH°	Enthalpy of sublimation at standard conditions

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