Phthalazine
- Formula: C8H6N2
- Molecular weight: 130.1466
- IUPAC Standard InChI: InChI=1S/C8H6N2/c1-2-4-8-6-10-9-5-7(8)3-1/h1-6H
- IUPAC Standard InChIKey: LFSXCDWNBUNEEM-UHFFFAOYSA-N
- CAS Registry Number: 253-52-1
- 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: Benzo[d]pyridazine; β-Phenodiazine; 2,3-Benzodiazine; 2,3-Diazanaphthalene
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
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.
Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Phase change 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 78.85 ± 0.79 | kcal/mol | Ccb | Ribeiro da Silva and Matos, 1995 | |
| ΔfH°gas | 82.5 ± 4.3 | kcal/mol | Ccb | Hussein and Akasheh, 1985 |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Phase change 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°solid | 59.18 ± 0.55 | kcal/mol | Ccb | Ribeiro da Silva and Matos, 1995 | |
| ΔfH°solid | 62.5 ± 4.1 | kcal/mol | Ccb | Hussein and Akasheh, 1985 | |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -1016.5 ± 0.50 | kcal/mol | Ccb | Ribeiro da Silva and Matos, 1995 | |
| ΔcH°solid | -1019.8 ± 4.0 | kcal/mol | Ccb | Hussein and Akasheh, 1985 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Condensed phase 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 as indicated in comments:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| Tfus | 364. | K | N/A | Sabbah and Pemenzi, 1993 | Uncertainty assigned by TRC = 0.1 K; TRC |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔsubH° | 19.8 ± 0.5 | kcal/mol | AVG | N/A | Average of 6 values; Individual data points |
Reduced pressure boiling point
| Tboil (K) | Pressure (atm) | Reference | Comment |
|---|---|---|---|
| 462.2 | 0.038 | Aldrich Chemical Company Inc., 1990 | BS |
| 448.2 | 0.022 | Weast and Grasselli, 1989 | BS |
Enthalpy of fusion
| ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 3.184 | 364.5 | Sabbah and Pemenzi, 1993 | AC |
Temperature of phase transition
| Ttrs (K) | Initial Phase | Final Phase | Reference | Comment |
|---|---|---|---|---|
| 364.41 | crystaline | liquid | Sabbah and Pemenzi, 1993, 2 | DH |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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 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
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 8.4 | PE | Van Den Ham and Van Der Meer, 1972 | LLK |
| 8.68 | PE | Dewar and Worley, 1969 | RDSH |
| 9.22 ± 0.01 | PI | Yencha and El-Sayed, 1968 | RDSH |
| 8.70 | PE | Van Den Ham and Van Der Meer, 1972 | Vertical value; LLK |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, 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]
Hussein and Akasheh, 1985
Hussein, A.; Akasheh, T.S.,
Heat of combustion of heterocyclic compounds. Part II.,
Dirasat - Univ. Jordan, 1985, 12, 65-72. [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]
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, 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]
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]
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]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
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 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.