- Formula: C3H4N2
- Molecular weight: 68.0773
- IUPAC Standard InChI:
- Download the identifier in a file.
- IUPAC Standard InChIKey: WTKZEGDFNFYCGP-UHFFFAOYSA-N
- CAS Registry Number: 288-13-1
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
- Other names: Pyrazole; 1,2-Diazole
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
Data at NIST subscription sites:
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.
Reaction thermochemistry data
Go To: Top, References, Notes
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.
C3H3N2- + =
By formula: C3H3N2- + H+ = C3H4N2
|rH°||1479. ± 10.||kJ/mol||G+TS||Gianola, Ichino, et al., 2006||gas phase; B|
|rH°||1479. ± 10.||kJ/mol||G+TS||Taft, Anvia, et al., 1986||gas phase; value altered from reference due to change in acidity scale; B|
|rG°||1449. ± 9.6||kJ/mol||N/A||Gianola, Ichino, et al., 2006||gas phase; B|
|rG°||1449. ± 9.6||kJ/mol||IMRE||Taft, Anvia, et al., 1986||gas phase; value altered from reference due to change in acidity scale; B|
+ = ( )
By formula: Li+ + C3H4N2 = (Li+ C3H4N2)
|rH°||187. ± 17.||kJ/mol||CIDT||Huang and Rodgers, 2002||RCD|
+ = ( )
By formula: Na+ + C3H4N2 = (Na+ C3H4N2)
|rH°||128. ± 9.2||kJ/mol||CIDT||Huang and Rodgers, 2002||RCD|
+ = ( )
By formula: K+ + C3H4N2 = (K+ C3H4N2)
|rH°||84. ± 3.||kJ/mol||CIDT||Huang and Rodgers, 2002||RCD|
Go To: Top, Reaction thermochemistry data, Notes
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]
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
rG° Free energy of reaction at standard conditions rH° 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.