1H-Pyrazole, 3-methyl-
- Formula: C4H6N2
- Molecular weight: 82.1038
- IUPAC Standard InChIKey: XKVUYEYANWFIJX-UHFFFAOYSA-N
- CAS Registry Number: 1453-58-3
- 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. - Other names: Pyrazole, 3-methyl-; Pyrazole, 5-methyl-; 3(5)-Methylpyrazole; 5-Methylpyrazole; Pyrazole, 3(or 5)-methyl-; 3-Methyl-1H-pyrazole; 3-Methylpyrazole
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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 as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 477.2 | K | N/A | Aldrich Chemical Company Inc., 1990 | BS |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 15.8 ± 0.48 | kcal/mol | C | Ribeiro da Silva, Figueiredo, et al., 2008 | AC |
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
C4H5N2- + =
By formula: C4H5N2- + H+ = C4H6N2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 356.0 ± 2.1 | kcal/mol | G+TS | Taft, 1991 | gas phase |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 348.3 ± 2.0 | kcal/mol | IMRE | Taft, 1991 | gas phase |
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 216.5 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 208.9 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
De-protonation reactions
C4H5N2- + =
By formula: C4H5N2- + H+ = C4H6N2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 356.0 ± 2.1 | kcal/mol | G+TS | Taft, 1991 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 348.3 ± 2.0 | kcal/mol | IMRE | Taft, 1991 | gas 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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Additional Data
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Due to licensing restrictions, this spectrum cannot be downloaded.
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 | NIST Mass Spectrometry Data Center |
NIST MS number | 340715 |
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
Column type | Active phase | Temperature (C) | I | Reference | Comment |
---|---|---|---|---|---|
Capillary | OV-101 | 110. | 930. | Golovnya, Kuz'menko, et al., 2000 | He; Phase thickness: 0.4 μm |
Capillary | OV-101 | 110. | 930. | Zhuravleva, 2000 | 50. m/0.3 mm/0.4 μm, He |
Van Den Dool and Kratz RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Packed | SE-30 | 930. | Peng, Ding, et al., 1988 | He, Supelcoport and Chromosorb, 40. C @ 4. min, 10. K/min, 250. C @ 60. min; Column length: 3.05 m |
References
Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc.,
Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]
Ribeiro da Silva, Figueiredo, et al., 2008
Ribeiro da Silva, Manuel A.V.; Figueiredo, Diogo F.; Cabral, Joana I.T.A.,
Thermochemical studies of 3-methylpyrazole and 1,3,5-trimethylpyrazole,
The Journal of Chemical Thermodynamics, 2008, 40, 3, 369-374, https://doi.org/10.1016/j.jct.2007.09.001
. [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]
Golovnya, Kuz'menko, et al., 2000
Golovnya, R.V.; Kuz'menko, T.E.; Krikunova, N.I.,
The influence of alkyl substituents on the chromatographic indicator of self-association of N-containing heterocyclic compounds,
Russ. Chem. Bull. (Engl. Transl.), 2000, 49, 2, 321-324, https://doi.org/10.1007/BF02494681
. [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]
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, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, References
- Symbols used in this document:
Tboil Boiling point ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH° Enthalpy of vaporization at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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