1H-Pyrazole

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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 as indicated in comments:
DRB - Donald R. Burgess, Jr.
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Δfgas42.40kcal/molN/AZaheeruddin and Lodhi, 1991Value computed using ΔfHsolid° value of 112.4 kj/mol from Zaheeruddin and Lodhi, 1991 and ΔsubH° value of 65.0 kj/mol from Jimenez, Roux, et al., 1987.; DRB
Δfgas42.9 ± 0.2kcal/molCcbJimenez, Roux, et al., 1987see Jimenez, Roux, et al., 1986; ALS
Δfgas43.3 ± 2.1kcal/molCcbBedford, Edmondson, et al., 1962ALS

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 as indicated in comments:
B - John E. Bartmess
RCD - Robert C. Dunbar

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

C3H3N2- + Hydrogen cation = 1H-Pyrazole

By formula: C3H3N2- + H+ = C3H4N2

Quantity Value Units Method Reference Comment
Δr353.6 ± 2.4kcal/molG+TSGianola, Ichino, et al., 2006gas phase; B
Δr353.6 ± 2.4kcal/molG+TSTaft, Anvia, et al., 1986gas phase; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr346.4 ± 2.3kcal/molN/AGianola, Ichino, et al., 2006gas phase; B
Δr346.4 ± 2.3kcal/molIMRETaft, Anvia, et al., 1986gas phase; value altered from reference due to change in acidity scale; B

Lithium ion (1+) + 1H-Pyrazole = (Lithium ion (1+) • 1H-Pyrazole)

By formula: Li+ + C3H4N2 = (Li+ • C3H4N2)

Quantity Value Units Method Reference Comment
Δr44.7 ± 4.0kcal/molCIDTHuang and Rodgers, 2002RCD

Sodium ion (1+) + 1H-Pyrazole = (Sodium ion (1+) • 1H-Pyrazole)

By formula: Na+ + C3H4N2 = (Na+ • C3H4N2)

Quantity Value Units Method Reference Comment
Δr30.6 ± 2.2kcal/molCIDTHuang and Rodgers, 2002RCD

Potassium ion (1+) + 1H-Pyrazole = (Potassium ion (1+) • 1H-Pyrazole)

By formula: K+ + C3H4N2 = (K+ • C3H4N2)

Quantity Value Units Method Reference Comment
Δr20.0 ± 0.8kcal/molCIDTHuang and Rodgers, 2002RCD

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 COBLENTZ SOC.
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. 06435
Date 1965/06/09
Name(s) 1H-pyrazole
State SOLUTION (5% CCl4 FOR 3800-1335, 5% CS2 FOR 1335-400)
Instrument BECKMAN IR-9 (GRATING)
Instrument parameters ORDER CHANGES: 670, 1200, 2000 CM-1
Path length 0.011 CM, 0.012 CM
SPECTRAL CONTAMINATION DUE TO CCl4 AROUND 1555, AND AN UNKNOWN AROUND 400 CM-1
Resolution 2
Sampling procedure TRANSMISSION
Data processing DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY
Melting point 70 C

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-5084
NIST MS number 230189

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 Knowles and Elguero, 1967
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. 19851
Instrument Cary 11
Melting point 70

Gas Chromatography

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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

Kovats' RI, non-polar column, isothermal

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Column type Active phase Temperature (C) I Reference Comment
CapillaryOV-101110.864.Zhuravleva, 200050. m/0.3 mm/0.4 μm, He
CapillaryOV-101110.864.Golovnya, Kuz'menko, et al., 199950. m/0.3 mm/0.4 μm, He

Van Den Dool and Kratz RI, non-polar column, temperature ramp

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Column type Active phase I Reference Comment
PackedSE-30837.Peng, Ding, et al., 1988He, Supelcoport and Chromosorb, 40. C @ 4. min, 10. K/min, 250. C @ 60. min; Column length: 3.05 m

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, Notes

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

Zaheeruddin and Lodhi, 1991
Zaheeruddin, M.; Lodhi, Z.H., Enthalpies of formation of some cyclic compounds, Phys. Chem. (Peshawar Pak.), 1991, 10, 111-118. [all data]

Jimenez, Roux, et al., 1987
Jimenez, P.; Roux, M.V.; Turrion, C., Thermochemical properties of N-heterocyclic compounds. I. Enthalpies of combustion, vapour pressures and enthalpies of sublimation, and enthalpies of formation of pyrazole, imidazole, indazole, and benzimidazole, J. Chem. Thermodyn., 1987, 19, 985-992. [all data]

Jimenez, Roux, et al., 1986
Jimenez, P.; Roux, M.V.; Turrion, C.; Gomis, F., Thermochemical properties of some N-heterocyclic compounds, J. Calorim. Anal. Therm. Thermodyn. Chim., 1986, 17, 469-470. [all data]

Bedford, Edmondson, et al., 1962
Bedford, A.F.; Edmondson, P.B.; Mortimer, C.T., Heats of formation and bond energies. Part VI. n-Butyliso-butyraldimine, n-butylisobutylamine, pyrazole, and imidazole, J. Chem. Soc., 1962, 2927-2931. [all data]

Gianola, Ichino, et al., 2006
Gianola, A.J.; Ichino, T.; Kato, S.; Bierbaum, V.M.; Lineberger, W.C., Thermochemical studies of pyrazolide, J. Phys. Chem. A, 2006, 110, 27, 8457-8466, https://doi.org/10.1021/jp057499+ . [all data]

Taft, Anvia, et al., 1986
Taft, R.W.; Anvia, F.; Taagepera, M.; Catalan, J.; Elgueroy, J., Electrostatic proximity effects in the relative basicities of pyrazole, imidazole, pyridazine, and pyrimidine, J. Am. Chem. Soc., 1986, 108, 3237. [all data]

Huang and Rodgers, 2002
Huang, H.; Rodgers, M.T., Sigma versus Pi interactions in alkali metal ion binding to azoles: Threshold collision-induced dissociation and ab initio theory studies, J. Phys. Chem. A, 2002, 106, 16, 4277, https://doi.org/10.1021/jp013630b . [all data]

Knowles and Elguero, 1967
Knowles, A.; Elguero, J., UV atlas of organic compounds, 1967, 3, G1/6. [all data]

Zhuravleva, 2000
Zhuravleva, I.L., Evaluation of the polarity and boiling points of nitrogen-containing heterocyclic compounds by gas chromatography, Russ. Chem. Bull. (Engl. Transl.), 2000, 49, 2, 325-328, https://doi.org/10.1007/BF02494682 . [all data]

Golovnya, Kuz'menko, et al., 1999
Golovnya, R.V.; Kuz'menko, T.E.; Zhuravleva, I.L., Gas chromatographic indicator of the ability of five- and six-membered heterocyclic nitrogen-containing compounds for self-association in pure liquids, Russ. Chem. Bull. (Engl. Transl.), 1999, 48, 4, 726-729, https://doi.org/10.1007/BF02496256 . [all data]

Peng, Ding, et al., 1988
Peng, C.T.; Ding, S.F.; Hua, R.L.; Yang, Z.C., Prediction of Retention Indexes I. Structure-Retention Index Relationship on Apolar Columns, J. Chromatogr., 1988, 436, 137-172, https://doi.org/10.1016/S0021-9673(00)94575-8 . [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, References