1H-Pyrazole, 3,4-dimethyl-

• Formula: C₅H₈N₂
• Molecular weight: 96.1304
• IUPAC Standard InChI: InChI=1S/C5H8N2/c1-4-3-6-7-5(4)2/h3H,1-2H3,(H,6,7) Copy

  
• IUPAC Standard InChIKey: VQTVFIMEENGCJA-UHFFFAOYSA-N Copy
• CAS Registry Number: 2820-37-3
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: 3(5),4-Dimethylpyrazole; Pyrazole, 3,4-dimethyl-
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• Information on this page:
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Mass spectrum (electron ionization)
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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 by: Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director

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

C₅H₇N₂^- +  =

By formula: C₅H₇N₂^- + H⁺ = C₅H₈N₂

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

Data compiled as indicated in comments:
B - John E. Bartmess

De-protonation reactions

C₅H₇N₂^- +  =

By formula: C₅H₇N₂^- + H⁺ = C₅H₈N₂

References

Go To: Top, Phase change data, Reaction thermochemistry 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.

Von Auwers and Kohlhaas, 1924
Von Auwers, K.; Kohlhaas, W., The Spectrochemistry of Heterocylic Nitrogen Compounds, Justus Liebigs Ann. Chem., 1924, 437, 36. [all data]

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

Notes

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• Symbols used in this document:
  

  Tfus	Fusion (melting) point
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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