1H-1,2,3-Triazole
- Formula: C2H3N3
- Molecular weight: 69.0653
- IUPAC Standard InChI: InChI=1S/C2H3N3/c1-2-4-5-3-1/h1-2H,(H,3,4,5)
- IUPAC Standard InChIKey: QWENRTYMTSOGBR-UHFFFAOYSA-N
- CAS Registry Number: 288-36-8
- 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: V-triazole; Osotriazole; Pyrrodiazole; Triazacyclopentadiene; 1,2,3-Triazole
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Reaction thermochemistry data
Go To: Top, 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 as indicated in comments:
B - John E. Bartmess
RCD - Robert C. Dunbar
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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
C2H2N3- + =
By formula: C2H2N3- + H+ = C2H3N3
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1449. ± 8.8 | kJ/mol | G+TS | Catalan, Claramunt, et al., 1988 | gas phase; The authors state the acidity is for the 2H isomer, which is more stable(G3MP2B3)in the gas phase than the 1H isomer by 3 kcal/mol. However, only the 1H isomer is commercially available; thus, this may not be a clean equilibrium.; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1419. ± 8.4 | kJ/mol | IMRE | Catalan, Claramunt, et al., 1988 | gas phase; The authors state the acidity is for the 2H isomer, which is more stable(G3MP2B3)in the gas phase than the 1H isomer by 3 kcal/mol. However, only the 1H isomer is commercially available; thus, this may not be a clean equilibrium.; B |
+
= (
•
)
By formula: Na+ + C2H3N3 = (Na+ • C2H3N3)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 95.8 ± 4.6 | kJ/mol | CIDT | Rodgers and Armentrout, 1999 | RCD |
Free energy of reaction
| ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 0.0 | 0. | CIDT | Rodgers and Armentrout, 1999 | RCD |
=
By formula: C2H3N3 = C2H3N3
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 12. | kJ/mol | Eqk | Mauret, Fayet, et al., 1973 | liquid phase; solvent: Benzene; ALS |
Gas phase ion energetics data
Go To: Top, 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
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| Proton affinity (review) | 879.3 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
| Quantity | Value | Units | Method | Reference | Comment |
| Gas basicity | 847.4 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 10.1 | PE | Palmer, Simpson, et al., 1981 | LLK |
| 10.06 | PE | Cradock, Findlay, et al., 1973 | Vertical value; LLK |
De-protonation reactions
C2H2N3- + =
By formula: C2H2N3- + H+ = C2H3N3
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1449. ± 8.8 | kJ/mol | G+TS | Catalan, Claramunt, et al., 1988 | gas phase; The authors state the acidity is for the 2H isomer, which is more stable(G3MP2B3)in the gas phase than the 1H isomer by 3 kcal/mol. However, only the 1H isomer is commercially available; thus, this may not be a clean equilibrium.; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1419. ± 8.4 | kJ/mol | IMRE | Catalan, Claramunt, et al., 1988 | gas phase; The authors state the acidity is for the 2H isomer, which is more stable(G3MP2B3)in the gas phase than the 1H isomer by 3 kcal/mol. However, only the 1H isomer is commercially available; thus, this may not be a clean equilibrium.; B |
Mass spectrum (electron ionization)
Go To: Top, Reaction thermochemistry data, 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: 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 | A. MAQUESTIAU |
| NIST MS number | 41816 |
References
Go To: Top, 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.
Catalan, Claramunt, et al., 1988
Catalan, J.; Claramunt, R.M.; Elguero, J.; Menedez, M.; Anvia, F.; Quian, J.H.; Taagepera, M.; Taft, R.W.,
Basicity and Acidity of Azoles. The Annelation Effect in Azoles.,
J. Am. Chem. Soc., 1988, 110, 13, 4107, https://doi.org/10.1021/ja00221a001
. [all data]
Rodgers and Armentrout, 1999
Rodgers, M.T.; Armentrout, P.B.,
Absolute Alkali Metal Ion Binding Affinities of Several Azoles Determined by Threshold Collision-Induced Dissociation,
Int. J. Mass Spectrom. Ion Proc., 1999, 185/186/187, 359. [all data]
Mauret, Fayet, et al., 1973
Mauret, P.; Fayet, J.P.; Fabre, M.; Elguero, J.; Pardo, M.d.C.,
Tautomerism study of υ-triazole from dipolar moment measurements,
J. Chim. Phys. Phys.-Chim. Biol., 1973, 70, 1483-1485. [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]
Palmer, Simpson, et al., 1981
Palmer, M.H.; Simpson, I.; Wheeler, J.R.,
Gas phase tautomerism in the triazoles and tetrazoles: A study by photoelectron spectroscopy and ab initio molecular orbital calculations,
Z. Naturforsch. A:, 1981, 36, 1246. [all data]
Cradock, Findlay, et al., 1973
Cradock, S.; Findlay, R.H.; Palmer, M.H.,
The molecular energy levels of the azoles: A study by photoelectron spectroscopy and ab initio molecular orbital calculations,
Tetrahedron, 1973, 29, 2173. [all data]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
T Temperature 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
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