Oxygen
- Formula: O2
- Molecular weight: 31.9988
- IUPAC Standard InChI: InChI=1S/O2/c1-2
- IUPAC Standard InChIKey: MYMOFIZGZYHOMD-UHFFFAOYSA-N
- CAS Registry Number: 7782-44-7
- 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: Molecular oxygen; Oxygen molecule; Pure oxygen; O2; Liquid oxygen; UN 1072; UN 1073; Dioxygen
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Gas phase ion energetics data
Go To: Top, 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
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to O2+ (ion structure unspecified)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| IE (evaluated) | 12.0697 ± 0.0002 | eV | N/A | N/A | L |
| Quantity | Value | Units | Method | Reference | Comment |
| Proton affinity (review) | 421. | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
| Quantity | Value | Units | Method | Reference | Comment |
| Gas basicity | 396.3 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.4480 ± 0.0060 | LPES | Ervin, Anusiewicz, et al., 2003 | B |
| 0.4510 ± 0.0070 | LPES | Travers, Cowles, et al., 1989 | B |
| 0.4400 ± 0.0080 | LPES | Celotta, Bennett, et al., 1972 | 89SAW puts DH(H-O2.) at 59 kcal/mol, implying ΔHacid=362.5; B |
| 0.451 ± 0.052 | ECD | Chen and Wentworth, 1983 | B |
| 0.44 ± 0.10 | CIDT | Tiernan and Wu, 1978 | From O2-; B |
| 0.40 ± 0.10 | NBIE | Durup, Parlant, et al., 1977 | B |
| 0.450 ± 0.024 | ETS | Burrow, 1974 | B |
| 0.50 ± 0.10 | NBIE | Baeda, 1972 | B |
| 0.430 ± 0.030 | LPES | Celotta, Bennett, et al., 1971 | B |
| 0.460 ± 0.050 | NBIE | Nalley and Compton, 1971 | B |
| >0.45 ± 0.10 | Endo | Tiernan, Hughes, et al., 1971 | B |
| 0.50 ± 0.20 | NBIE | Lacmann and Herschbach, 1970 | B |
| 0.430 ± 0.020 | Kine | Pack and Phelps, 1966 | B |
| >0.479998 | Endo | Berkowitz, Chupka, et al., 1971 | B |
| >0.56 ± 0.10 | Endo | Chantry, 1971 | B |
| 0.725005 | ECD | Chen and Chen, 2003 | B |
| >1.27 ± 0.20 | Endo | Bailey and Mahadevan, 1970 | B |
| 1.119 ± 0.069 | IMRB | Vogt, Hauffle, et al., 1970 | B |
| >1.10 ± 0.10 | EIAE | Stockdale, Compton, et al., 1969 | From NO2; B |
| 0.150 ± 0.050 | PD | Burch, Smith, et al., 1958 | B |
Proton affinity at 298K
| Proton affinity (kJ/mol) | Reference | Comment |
|---|---|---|
| 421. ± 3. | Litorja and Ruscic, 1998 | T = 298K; MM |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 12.0697 ± 0.0002 | S | Tonkyn, Winniczek, et al., 1989 | LL |
| 12.1 ± 0.1 | EI | Grade, Wienecke, et al., 1983 | LBLHLM |
| 12.8 ± 0.5 | EI | Gomez, Chatillon, et al., 1982 | LBLHLM |
| 12.0 ± 1.0 | S | Farber, Srivastava, et al., 1982 | LBLHLM |
| 12.076 ± 0.002 | PE | MacNeil and Dixon, 1977 | LLK |
| 12.071 | PE | Kronebusch and Berkowitz, 1976 | LLK |
| 12.071 ± 0.001 | PE | Samson and Gardner, 1975 | LLK |
| 12.0 ± 0.5 | EI | Hildenbrand, 1975 | LLK |
| 12.2 ± 0.2 | EI | Bennett, Lin, et al., 1974 | LLK |
| 12.07 ± 0.01 | PI | Tanaka and Tanaka, 1973 | LLK |
| 12.08 | PE | Natalis, 1973 | LLK |
| 12.077 | PE | Dromey, Morrison, et al., 1973 | LLK |
| 12.127 | PE | Vilesov and Lopatin, 1972 | LLK |
| 12.072 ± 0.008 | PI | Dibeler and Walker, 1967 | RDSH |
| 12.059 ± 0.001 | S | Samson and Cairns, 1966 | RDSH |
| 12.078 ± 0.005 | PI | Brehm, 1966 | RDSH |
| 12.065 ± 0.003 | PI | Nicholson, 1963 | RDSH |
| 12.08 ± 0.01 | PI | Watanabe, 1957 | RDSH |
| 12.30 | PE | Kimura, Katsumata, et al., 1981 | Vertical value; LLK |
| 12.33 ± 0.01 | PE | Banna and Shirley, 1976 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| O+ | 18.734 | O | PIPECO | Blyth, Powis, et al., 1981 | LLK |
| O+ | 17.28 | O- | PI | Oertel, Schenk, et al., 1980 | LLK |
| O+ | 18.69 ± 0.04 | O | EI | Locht and Schopman, 1974 | LLK |
| O+ | 17.3 ± 0.2 | O- | EI | Locht and Momigny, 1971 | LLK |
| O+ | 17.25 ± 0.01 | O- | PI | Dibeler and Walker, 1967 | RDSH |
| O+ | 17.272 ± 0.024 | O- | PI | Elder, Villarejo, et al., 1965 | RDSH |
| O+ | 18.8 ± 0.4 | O | PI | Weissler, Samson, et al., 1959 | RDSH |
| O+ | 18.99 ± 0.05 | O | EI | Frost and McDowell, 1959 | RDSH |
Anion protonation reactions
+
=
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1476.9 ± 3.0 | kJ/mol | D-EA | Travers, Cowles, et al., 1989 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1450.5 ± 3.4 | kJ/mol | H-TS | Travers, Cowles, et al., 1989 | gas phase; B |
Mass spectrum (electron ionization)
Go To: Top, 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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| 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 | D.HENNEBERG, MAX-PLANCK INSTITUTE, MULHEIM, WEST GERMANY |
| NIST MS number | 61306 |
References
Go To: Top, 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.
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]
Ervin, Anusiewicz, et al., 2003
Ervin, K.M.; Anusiewicz, W.; Skurski, P.; Simons, J.; Lineberger, W.C.,
The only stable state of O-2(-) is the X (2)Pi(g) ground state and it (still!) has an adiabatic electron detachment energy of,
J. Phys. Chem. A, 2003, 107, 41, 8521-8529, https://doi.org/10.1021/jp0357323
. [all data]
Travers, Cowles, et al., 1989
Travers, M.J.; Cowles, D.C.; Ellison, G.B.,
Reinvestigation of the Electron Affinities of O2 and NO,
Chem. Phys. Lett., 1989, 164, 5, 449, https://doi.org/10.1016/0009-2614(89)85237-6
. [all data]
Celotta, Bennett, et al., 1972
Celotta, R.J.; Bennett, R.A.; Hall, J.L.; Siegel, M.W.; Levine, J.,
Molecular photodetachment spectrometry. II. The electron affinity of O2 and the structure of O2-,
Phys. Rev. A:, 1972, 6, 631. [all data]
Chen and Wentworth, 1983
Chen, E.C.M.; Wentworth, W.E.,
Determination of molecular electron affinities using the electron capture detector in the pulse sampling mode at steady state,
J. Phys. Chem., 1983, 87, 45. [all data]
Tiernan and Wu, 1978
Tiernan, T.O.; Wu, R.L.C.,
Thermochemical Data for Molecular Negative Ions from Collisional Dissociation Thresholds,
Adv. Mass Spectrom., 1978, 7A, 136. [all data]
Durup, Parlant, et al., 1977
Durup, M.; Parlant, G.; Appell, J.; Durup, J.; Ozenne, J.-B.,
Translational spectroscopy of neutralization-reionization double collision processes of Ar+ ions at keV energies,
Chem. Phys., 1977, 25, 245. [all data]
Burrow, 1974
Burrow, P.D.,
Temporary negative ion formation in NO and O2,
Chem. Phys. Lett., 1974, 26, 265. [all data]
Baeda, 1972
Baeda, A.P.M.,
The adiabatic electron affinities of Cl2, Br2, I2, IBr, NO2, and O2,
Physica, 1972, 59, 541. [all data]
Celotta, Bennett, et al., 1971
Celotta, R.J.; Bennett, R.A.; Hall, J.L.; Levine, J.; Siegel, M.W.,
Electron affinity of O2 by laser photodetachment,
Bull. Am. Phys. Soc., 1971, 16, 212. [all data]
Nalley and Compton, 1971
Nalley, S.J.; Compton, R.N.,
Collisional ionization of cesium by oxygen: The electron affinity of O2,
Chem. Phys. Lett., 1971, 9, 529. [all data]
Tiernan, Hughes, et al., 1971
Tiernan, T.O.; Hughes, B.M.; Lifschitz, C.,
Electron affinities from endothermic negative ion charge transfer reactions. II. O2,
J. Chem. Phys., 1971, 55, 5692. [all data]
Lacmann and Herschbach, 1970
Lacmann, K.; Herschbach, D.R.,
Collisional Excitation and Ionization of K Atoms by Diatomic Molecules: Role of Ion-pair States,
Chem. Phys. Lett., 1970, 6, 2, 106, https://doi.org/10.1016/0009-2614(70)80144-0
. [all data]
Pack and Phelps, 1966
Pack, J.L.; Phelps, A.V.,
Electron Attachment and Detachment. I. Pure O2 at Low Energy,
J. Chem. Phys., 1966, 44, 5, 1870, https://doi.org/10.1063/1.1726956
. [all data]
Berkowitz, Chupka, et al., 1971
Berkowitz, J.; Chupka, W.A.; Gutman, D.,
Electron Affinities of O2, O3, NO, NO2, and NO3 by Endothermic Charge Transfer,
J. Chem. Phys., 1971, 55, 6, 2733, https://doi.org/10.1063/1.1676488
. [all data]
Chantry, 1971
Chantry, P.J.,
Doppler broadening in beam experiments,
J. Chem. Phys., 1971, 55, 2746. [all data]
Chen and Chen, 2003
Chen, E.S.; Chen, E.C.M.,
Semiempirical characterization of homonuclear diatomic ions: 6. Group VI and VII anions,
J. Phys. Chem. A, 2003, 107, 1, 169-177, https://doi.org/10.1021/jp0268922
. [all data]
Bailey and Mahadevan, 1970
Bailey, T.L.; Mahadevan, P.,
Electron Transfer and Detachment in Collisions of Low Energy Negative Ions with O2,
J. Chem. Phys., 1970, 52, 1, 179, https://doi.org/10.1063/1.1672663
. [all data]
Vogt, Hauffle, et al., 1970
Vogt, D.; Hauffle, B.; Neuert, H.,
Ladungsaustausch-Reaktionen Einiger Negativer Ionen mit O2 und die Elektronenaffinitat des O2,
Z. Phys., 1970, 232, 5, 439, https://doi.org/10.1007/BF01395674
. [all data]
Stockdale, Compton, et al., 1969
Stockdale, J.A.D.; Compton, R.N.; Hurst, G.S.; Reinhardt, P.W.,
Collisions of Monoenergetic Electrons with NO2: Possible Lower Limits to the Electron Affinities of O2 and NO,
J. Chem. Phys., 1969, 50, 5, 2176, https://doi.org/10.1063/1.1671347
. [all data]
Burch, Smith, et al., 1958
Burch, D.S.; Smith, S.J.; Branscomb, L.M.,
Photodetachment of O2-.,
Phys. Rev., 1958, 112, 1, 171, https://doi.org/10.1103/PhysRev.112.171
. [all data]
Litorja and Ruscic, 1998
Litorja, M.; Ruscic, B.,
A photoionization study of the hydroperoxyl radical, HO2, and hydrogen peroxide, H2O2,
J. Electron Spectroscopy and Related Phenomena, 1998, 97, 131. [all data]
Tonkyn, Winniczek, et al., 1989
Tonkyn, R.G.; Winniczek, J.W.; White, M.G.,
Rotationally resolved photoionization of O2 near threshold,
Chem. Phys. Lett., 1989, 164, 137. [all data]
Grade, Wienecke, et al., 1983
Grade, M.; Wienecke, J.; Rosinger, W.; Hirschwald, W.,
Electron impact investigation of the molecules SeS(g) and TeSe(g) under high-temperature equilibrium conditions,
Ber. Bunsen-Ges. Phys. Chem., 1983, 87, 355. [all data]
Gomez, Chatillon, et al., 1982
Gomez, M.; Chatillon, C.; Allibert, M.,
Thermodynamics of gaseous and condensed indium oxides by mass spectrometry with controlled oxygen oressure,
J. Chem. Thermodyn., 1982, 14, 447. [all data]
Farber, Srivastava, et al., 1982
Farber, M.; Srivastava, R.D.; Moyer, J.W.,
Mass spectrometric determination of the thermodynamics of potassium hydroxide and minor potassium-containing species required in magnetohydrodynamic power systems,
J. Chem. Thermodyn., 1982, 14, 1103. [all data]
MacNeil and Dixon, 1977
MacNeil, K.A.G.; Dixon, R.N.,
High-resolution photoelectron spectroscopy of methanol and its deuterated derivatives: Internal rotation in the ground ionic state,
J. Electron Spectrosc. Relat. Phenom., 1977, 11, 315. [all data]
Kronebusch and Berkowitz, 1976
Kronebusch, P.L.; Berkowitz, J.,
Photodissociative ionization in the 21-41 eV region: O2, N2, CO, NO, CO2, H2O, NH3 and CH4,
Int. J. Mass Spectrom. Ion Phys., 1976, 22, 283. [all data]
Samson and Gardner, 1975
Samson, J.A.R.; Gardner, J.L.,
On the ionization potential of molecular oxygen,
Can. J. Phys., 1975, 53, 1948. [all data]
Hildenbrand, 1975
Hildenbrand, D.L.,
Vertical ionization potential of the CF2 radical,
Chem. Phys. Lett., 1975, 32, 30. [all data]
Bennett, Lin, et al., 1974
Bennett, S.L.; Lin, S.-S.; Gilles, P.W.,
High-temperature vaporization of ternary systems. I. Mass spectrometry of oxygen-rich vanadium-tungsten-oxygen species,
J. Phys. Chem., 1974, 78, 266. [all data]
Tanaka and Tanaka, 1973
Tanaka, K.; Tanaka, I.,
Photoelectron spectra from some autoionizing state of O2 near the ionization threshold,
J. Chem. Phys., 1973, 59, 5042. [all data]
Natalis, 1973
Natalis, P.,
Contribution a la spectroscopie photoelectronique. Effets de l'autoionisation dans less spectres photoelectroniques de molecules diatomiques et triatomiques,
Acad. R. Belg. Mem. Cl. Sci. Collect. 8, 1973, 41, 1. [all data]
Dromey, Morrison, et al., 1973
Dromey, R.G.; Morrison, J.D.; Peel, J.B.,
Time-averaged and deconvoluted photoelectron spectrum of the first band of O2,
Chem. Phys. Lett., 1973, 23, 30. [all data]
Vilesov and Lopatin, 1972
Vilesov, F.I.; Lopatin, S.N.,
Photoelectron spectrometer,
Zh. Tekh. Fiz., 1972, 42, 176. [all data]
Dibeler and Walker, 1967
Dibeler, V.H.; Walker, J.A.,
Mass spectrometric study of the photoionization of small polyatomic molecules,
Advan. Mass Spectrom., 1967, 4, 767. [all data]
Samson and Cairns, 1966
Samson, J.A.R.; Cairns, R.B.,
Ionization potential of O2,
J. Opt. Soc. Am., 1966, 56, 769. [all data]
Brehm, 1966
Brehm, B.,
Massenspektrometrische Untersuchung der Photoionisation von Molekulen,
Z. Naturforsch., 1966, 21a, 196. [all data]
Nicholson, 1963
Nicholson, A.J.C.,
Photo-ionization efficiency curves. Measurement of ionization potentials and interpretation of fine structure,
J. Chem. Phys., 1963, 39, 954. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Banna and Shirley, 1976
Banna, M.S.; Shirley, D.A.,
Molecular photoelectron spectroscopy at 132.3 eV: N2, CO, C2H4 and O2,
J. Electron Spectrosc. Relat. Phenom., 1976, 8, 255. [all data]
Blyth, Powis, et al., 1981
Blyth, R.C.G.; Powis, I.; Danby, C.J.,
Competing pre-dissociations of O2+(B 2Σg-),
Chem. Phys. Lett., 1981, 84, 272. [all data]
Oertel, Schenk, et al., 1980
Oertel, H.; Schenk, H.; Baumgartel, H.,
Ion pair formation from photon irradiation of O2, NO and CO in 17-30 eV,
Chem. Phys., 1980, 46, 251. [all data]
Locht and Schopman, 1974
Locht, R.; Schopman, J.,
The dissociative ionization in oxygen,
Int. J. Mass Spectrom. Ion Phys., 1974, 15, 361. [all data]
Locht and Momigny, 1971
Locht, R.; Momigny, J.,
Mass spectrometric study of ion-pair processes in diatomic molecules: H2, CO, NO and O2,
Int. J. Mass Spectrom. Ion Phys., 1971, 7, 121. [all data]
Elder, Villarejo, et al., 1965
Elder, F.A.; Villarejo, D.; Inghram, M.G.,
Electron affinity of oxygen,
J. Chem. Phys., 1965, 43, 758. [all data]
Weissler, Samson, et al., 1959
Weissler, G.L.; Samson, J.A.R.; Ogawa, M.; Cook, G.R.,
Photoionization analysis by mass spectroscopy,
J. Opt. Soc. Am., 1959, 49, 338. [all data]
Frost and McDowell, 1959
Frost, D.C.; McDowell, C.A.,
Recent electron impact studies on simple molecules (O2, Cl2, I2),
Advan. Mass Spectrom., 1959, 1, 413. [all data]
Notes
Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
AE Appearance energy EA Electron affinity IE (evaluated) Recommended ionization energy 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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