Quinoxaline
- Formula: C8H6N2
- Molecular weight: 130.1466
- IUPAC Standard InChIKey: XSCHRSMBECNVNS-UHFFFAOYSA-N
- CAS Registry Number: 91-19-0
- 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: Benzoparadiazine; Benzopyrazine; Benzo[a]pyrazine; Phenopiazine; Phenpiazine; Quinazine; 1,4-Benzodiazine; 1,4-Diazanaphthalene; 1,4-Naphthyridine; USAF EK-7094
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 240.3 ± 3.3 | kJ/mol | Ccb | Ribeiro da Silva and Matos, 1995 |
Condensed 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | 173.7 ± 2.6 | kJ/mol | Ccb | Ribeiro da Silva and Matos, 1995 | |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -4179.3 ± 2.4 | kJ/mol | Ccb | Ribeiro da Silva and Matos, 1995 |
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
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 494.7 | K | N/A | Aldrich Chemical Company Inc., 1990 | BS |
Tboil | 502.7 | K | N/A | Weast and Grasselli, 1989 | BS |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 306. | K | N/A | Sabbah and Pemenzi, 1993 | Uncertainty assigned by TRC = 0.1 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 66.6 ± 2.0 | kJ/mol | C | Ribeiro da Silva and Matos, 1995 | ALS |
ΔsubH° | 66.6 | kJ/mol | N/A | Ribeiro da Silva and Matos, 1995 | DRB |
ΔsubH° | 66.6 ± 2.0 | kJ/mol | C | da Silva, Matos, et al., 1995 | AC |
ΔsubH° | 69.4 ± 0.6 | kJ/mol | C | Sabbah and Pemenzi, 1993 | AC |
Enthalpy of sublimation
ΔsubH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
69.390 | 298.15 | Sabbah and Pemenzi, 1993, 2 | DH |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
11.8 | 305.7 | Sabbah and Pemenzi, 1993 | AC |
Temperature of phase transition
Ttrs (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|
305.68 | crystaline | liquid | Sabbah and Pemenzi, 1993, 2 | DH |
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
L - Sharon G. Lias
Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 9.01 ± 0.01 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 903.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 873.7 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
0.71 ± 0.10 | IMRE | Dillow and Kebarle, 1989 | ΔGea(423 K) =-15.8 kcal/mol; ΔSea (estimated) =-1.5, taken as that of anthracene. 1,4-diazabenzene; B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.01 | PE | Brogli, Heilbronner, et al., 1972 | LLK |
8.99 | PE | Dewar and Worley, 1969 | RDSH |
9.02 ± 0.01 | PI | Yencha and El-Sayed, 1968 | RDSH |
9.00 | PE | Van Den Ham and Van Der Meer, 1972 | Vertical value; LLK |
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: NIST Mass Spectrometry Data Center, William E. Wallace, director
Gas Phase Spectrum
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Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.
Additional Data
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Owner | SRD/NIST Collection (C) 2018 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | EPA-IR VAPOR PHASE LIBRARY |
State | gas |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, 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
View image of digitized spectrum (can be printed in landscape orientation).
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 | Japan AIST/NIMC Database- Spectrum MS-NW-3560 |
NIST MS number | 227885 |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, 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.
Ribeiro da Silva and Matos, 1995
Ribeiro da Silva, M.A.V.; Matos, M.A.R.,
Thermochemical and theoretical studies of some benzodiazines,
J. Chem. Soc. Faraday Trans., 1995, 91, 1907-1910. [all data]
Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc.,
Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]
Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]
Sabbah and Pemenzi, 1993
Sabbah, R.; Pemenzi, O.,
Energetics of intermolecular bonds in the three diazines: phthalazine, quinazoline and quinoxaline,
C. R. Acad. Sci. Paris, Ser. II, 1993, 317, 5, 575. [all data]
da Silva, Matos, et al., 1995
da Silva, Manuel A.V. Ribeiro; Matos, M. Agostinha R.; Morais, Victor M.F.,
Thermochemical and theoretical studies of some benzodiazines,
Faraday Trans., 1995, 91, 13, 1907, https://doi.org/10.1039/ft9959101907
. [all data]
Sabbah and Pemenzi, 1993, 2
Sabbah, R.; Pemenzi, O.,
Energetique des liaisons intermoleculaires dans les molecules de phthalazine, quinazoline, and quinoxaline, Compt. Rend. Acad. Sci. Paris,
Series II, 1993, 317, 575-581. [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]
Dillow and Kebarle, 1989
Dillow, G.W.; Kebarle, P.,
Electron Affinities of aza-substituted polycyclic aromatic hydrocarbons,
Can. J. Chem., 1989, 67, 10, 1628, https://doi.org/10.1139/v89-249
. [all data]
Brogli, Heilbronner, et al., 1972
Brogli, F.; Heilbronner, E.; Kobayashi, T.,
Photoelectron spectra of azabenzenes and azanaphthalenes: II. A reinvestigation of azanaphthalenes by high-resolution photoelectron spectroscopy,
Helv. Chim. Acta, 1972, 55, 274. [all data]
Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D.,
Photoelectron spectra of molecules. II.The ionization potentials of azabenzenes and azanaphthalenes,
J. Chem. Phys., 1969, 51, 263. [all data]
Yencha and El-Sayed, 1968
Yencha, A.J.; El-Sayed, M.A.,
Lowest ionization potentials of some nitrogen heterocyclics,
J. Chem. Phys., 1968, 48, 3469. [all data]
Van Den Ham and Van Der Meer, 1972
Van Den Ham, D.M.W.; Van Der Meer, D.,
The photoelectron spectra of the diazanaphthalenes,
Chem. Phys. Lett., 1972, 12, 447. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), References
- Symbols used in this document:
EA Electron affinity IE (evaluated) Recommended ionization energy Tboil Boiling point Tfus Fusion (melting) point Ttrs Temperature of phase transition ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions ΔfusH Enthalpy of fusion ΔsubH Enthalpy of sublimation ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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