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-
• 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
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Mass spectrum (electron ionization)
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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.

Phase change data

Go To: Top, 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 by: Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director

Gas phase ion energetics data

Go To: Top, 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

De-protonation reactions

C₅H₇N₂^- +  =

By formula: C₅H₇N₂^- + H⁺ = C₅H₈N₂

References

Go To: Top, 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.

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]

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]

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

Notes

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

• 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
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.