1H-Pyrazole, 3,4-dimethyl-

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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

Quantity Value Units Method Reference Comment
Tfus331.15KN/AVon Auwers and Kohlhaas, 1924Uncertainty assigned by TRC = 1.5 K

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

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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: 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- + Hydrogen cation = 1H-Pyrazole, 3,4-dimethyl-

By formula: C5H7N2- + H+ = C5H8N2

Quantity Value Units Method Reference Comment
Δr355.7 ± 2.1kcal/molG+TSTaft, 1991gas phase
Quantity Value Units Method Reference Comment
Δr348.0 ± 2.0kcal/molIMRETaft, 1991gas phase

Gas phase ion energetics data

Go To: Top, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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

Quantity Value Units Method Reference Comment
Proton affinity (review)221.6kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity214.0kcal/molN/AHunter and Lias, 1998HL

De-protonation reactions

C5H7N2- + Hydrogen cation = 1H-Pyrazole, 3,4-dimethyl-

By formula: C5H7N2- + H+ = C5H8N2

Quantity Value Units Method Reference Comment
Δr355.7 ± 2.1kcal/molG+TSTaft, 1991gas phase; B
Quantity Value Units Method Reference Comment
Δr348.0 ± 2.0kcal/molIMRETaft, 1991gas phase; B

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 L.E. Slivon, Battelle Columbus Laboratories, Columbus, Ohio 43201
NIST MS number 70656

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References

Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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

Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References