Oxygen, atomic

Formula: O
Molecular weight: 15.9994
IUPAC Standard InChI: InChI=1S/O
IUPAC Standard InChIKey: QVGXLLKOCUKJST-UHFFFAOYSA-N
CAS Registry Number: 17778-80-2
Chemical structure:
This structure is also available as a 2d Mol file
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- Gas phase thermochemistry data
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Reaction thermochemistry data

Go To: Top, Gas phase ion energetics data, References, Notes

Data compiled by: John E. Bartmess

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

( • 4294967295 Oxygen, atomic ) + =

By formula: (HO^- • 4294967295O) + O = HO^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	533.21	kJ/mol	N/A	Smith, Kim, et al., 1997	gas phase; Given: 14741.02(3) cm-1. dHacid(0K) = 389.11±0.014
Δ_rH°	533.88 ± 0.84	kJ/mol	Ther	Schulz, Mead, et al., 1982	gas phase; Given: 1.82767±0.00021 eV

(CAS Reg. No. 661-20-1 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 661-20-1

By formula: (CAS Reg. No. 661-20-1 • 4294967295O) + O = CAS Reg. No. 661-20-1

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	530.99	kJ/mol	N/A	Bradforth, Kim, et al., 1993	gas phase; D-EA cycle requires a DH ca 4 kcal/mol weaker
Δ_rH°	516.10	kJ/mol	Ther	Wight and Beauchamp, 1980	gas phase

( • 4294967295 Oxygen, atomic ) + =

By formula: (O₂^- • 4294967295O) + O = O₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	400.7	kJ/mol	N/A	Ervin, Anusiewicz, et al., 2003	gas phase
Δ_rH°	401. ± 4.2	kJ/mol	Ther	Travers, Cowles, et al., 1989	gas phase

(CAS Reg. No. 13981-20-9 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 13981-20-9

By formula: (CAS Reg. No. 13981-20-9 • 4294967295O) + O = CAS Reg. No. 13981-20-9

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	524. ± 30.	kJ/mol	CIDT	Bell, Zemski, et al., 2001	gas phase

(CAS Reg. No. 14380-61-1 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 14380-61-1

By formula: (CAS Reg. No. 14380-61-1 • 4294967295O) + O = CAS Reg. No. 14380-61-1

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	140.0	kJ/mol	N/A	Distelrath and Boesl, 2000	gas phase

(CAS Reg. No. 12763-66-5 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 12763-66-5

By formula: (CAS Reg. No. 12763-66-5 • 4294967295O) + O = CAS Reg. No. 12763-66-5

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	110.6	kJ/mol	N/A	Gilles, Polak, et al., 1992	gas phase

(CAS Reg. No. 14380-62-2 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 14380-62-2

By formula: (CAS Reg. No. 14380-62-2 • 4294967295O) + O = CAS Reg. No. 14380-62-2

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	136.1	kJ/mol	N/A	Gilles, Polak, et al., 1992	gas phase

(CAS Reg. No. 15065-65-3 • 4294967295 Oxygen, atomic ) + = CAS Reg. No. 15065-65-3

By formula: (CAS Reg. No. 15065-65-3 • 4294967295O) + O = CAS Reg. No. 15065-65-3

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	168.2	kJ/mol	N/A	Gilles, Polak, et al., 1991	gas phase

Gas phase ion energetics data

Go To: Top, Reaction thermochemistry data, References, Notes

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
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 O⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	13.61806	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	485.2	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	459.6	kJ/mol	N/A	Hunter and Lias, 1998	HL

Electron affinity determinations

EA (eV)	Method	Reference	Comment
1.439157 ± 0.000004	LPD	Joiner, Mohr, et al., 2011	Given: 11607.75(28) cm-1. In 1.0 T field, 0.5 kcal/mol lower than "best" EA; B
1.4610 ± 0.0010	LPES	Cavanagh, Gibson, et al., 2007	B
1.460982 ± 0.000044	LPD	Blondel, Chaibi, et al., 2005	(16)O: 1.4611135(12) eV: revised analysis of Blondel, Delsart, et al., 2001; B
1.461112 ± 0.000044	LPD	Neumark, Lykke, et al., 1985	Given: 1.461122(3) eV; revised to 1.4611107(17) eV, 95BLO, based on missing term+86CODATA; B
1.461112 ± 0.000044	N/A	Valli, Blondel, et al., 1999	16O: 11784.682(20) cm-1; 18O: 11784.612(29) cm-1 or 8.7μeV lower.; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
13.61806	EVAL	Lide, 1992	LL
13.618	S	Kelly, 1987	LBLHLM
13.0 ± 0.5	EI	Banon, Chatillon, et al., 1982	LBLHLM
13.618	PI	Radler and Berkowitz, 1977	LLK
14. ± 1.	EI	Paule, 1976	LLK
14.0 ± 0.5	EI	Hildenbrand, 1975	LLK
13.618	S	Cermak, 1975	LLK
13.61806	S	Moore, 1970	RDSH
13.62	PE	Jonathan, Morris, et al., 1970	RDSH

Anion protonation reactions

O^- + =

By formula: O^- + H⁺ = HO

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1600.798 ± 0.042	kJ/mol	D-EA	Neumark, Lykke, et al., 1985	gas phase; Given: 1.461122(3) eV; revised to 1.4611107(17) eV, 95BLO, based on missing term+86CODATA; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1576.2 ± 0.63	kJ/mol	H-TS	Neumark, Lykke, et al., 1985	gas phase; Given: 1.461122(3) eV; revised to 1.4611107(17) eV, 95BLO, based on missing term+86CODATA; B

References

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Notes

Smith, Kim, et al., 1997
Smith, J.R.; Kim, J.B.; Lineberger, W.C., High-resolution Threshold Photodetachment Spectroscopy of OH-, Phys. Rev. A, 1997, 55, 3, 2036, https://doi.org/10.1103/PhysRevA.55.2036 . [all data]

Schulz, Mead, et al., 1982
Schulz, P.A.; Mead, R.D.; Jones, P.L.; Lineberger, W.C., OH- and OD- threshold photodetachment, J. Chem. Phys., 1982, 77, 1153. [all data]

Bradforth, Kim, et al., 1993
Bradforth, S.E.; Kim, E.H.; Arnold, D.W.; Neumark, D.M., Photoelectron Spectroscopy of CN-, NCO-, and NCS-, J. Chem. Phys., 1993, 98, 2, 800, https://doi.org/10.1063/1.464244 . [all data]

Wight and Beauchamp, 1980
Wight, C.A.; Beauchamp, J.L., Acidity, basicity, and ion/molecule reactions of isocyanic acid in the gas phase by ICR spectroscopy, J. Phys. Chem., 1980, 84, 2503. [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]

Bell, Zemski, et al., 2001
Bell, R.C.; Zemski, K.A.; Justes, D.R.; Castleman, A.W., Formation, structure and bond dissociation thresholds of gas- phase vanadium oxide cluster ions, J. Chem. Phys., 2001, 114, 2, 798-811, https://doi.org/10.1063/1.1329643 . [all data]

Distelrath and Boesl, 2000
Distelrath, V.; Boesl, U., Mass selective gas phase study of ClO, OClO, ClOO and ClAr by anion-ZEKE-photoelectron spectroscopy, Faraday Disc. Chem. Soc., 2000, 115, 161-174, https://doi.org/10.1039/a909618c . [all data]

Gilles, Polak, et al., 1992
Gilles, M.K.; Polak, M.L.; Lineberger, W.C., Photoelectron Spectroscopy of the Halogen Oxide Anions FO-, ClO-, BrO-, IO-, OClO-, and OIO-, J. Chem. Phys., 1992, 96, 11, 8012, https://doi.org/10.1063/1.462352 . [all data]

Gilles, Polak, et al., 1991
Gilles, M.K.; Polak, M.L.; Lineberger, W.C., Photoelectron Spectroscopy of IO-, J. Chem. Phys., 1991, 95, 6, 4723, https://doi.org/10.1063/1.461746 . [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]

Joiner, Mohr, et al., 2011
Joiner, A.; Mohr, R.H.; Yukich, J.N., High-resolution photodetachment spectroscopy from the lowest threshold of O-, Phys. Rev. A, 2011, 83, 3, 035401, https://doi.org/10.1103/PhysRevA.83.035401 . [all data]

Cavanagh, Gibson, et al., 2007
Cavanagh, S.J.; Gibson, S.T.; Gale, M.N.; Dedman, C.J.; Roberts, E.H.; Lewis, B.R., High-resolution velocity-map-imaging photoelectron spectroscopy of the O- photodetachment fine-structure transitions, Phys. Rev. A, 2007, 76, 5, 052708, https://doi.org/10.1103/PhysRevA.76.052708 . [all data]

Blondel, Chaibi, et al., 2005
Blondel, C.; Chaibi, W.; Delsart, C.; Drag, C.; Goldfarb, F.; Kroger, S., The electron affinities of O, Si, and S revisited with the photodetachment microscope, Eur. Phys. J. D, 2005, 33, 3, 335-342, https://doi.org/10.1140/epjd/e2005-00069-9 . [all data]

Blondel, Delsart, et al., 2001
Blondel, C.; Delsart, C.; Goldfarb, F., Electron spectrometry at the mu eV level and the electron affinities of Si and F, J. Phys. B: Atom. Mol. Opt. Phys., 2001, 34, 9, L281-L288, https://doi.org/10.1088/0953-4075/34/9/101 . [all data]

Neumark, Lykke, et al., 1985
Neumark, D.M.; Lykke, K.R.; Andersen, T.; Lineberger, W.C., Laser photodetachment measurement of the electron affinity of atomic oxygen, Phys. Rev. A:, 1985, 32, 1890. [all data]

Valli, Blondel, et al., 1999
Valli, C.; Blondel, C.; Delsart, C., Measuring electron affinities with the photodetachment microscope, Phys. Rev. A, 1999, 59, 5, 3809-3815, https://doi.org/10.1103/PhysRevA.59.3809 . [all data]

Lide, 1992
Lide, D.R. (Editor), Ionization potentials of atoms and atomic ions in Handbook of Chem. and Phys., 1992, 10-211. [all data]

Kelly, 1987
Kelly, R.L., Atomic and ionic spectrum lines of hydrogen through kryton, J. Phys. Chem. Ref. Data, 1987, 16. [all data]

Banon, Chatillon, et al., 1982
Banon, S.; Chatillon, C.; Allibert, M., High temperature mass spectrometric study of ionization and fragmentation of TiO and TiO₂ gas under electron impact, High Temp. Sci., 1982, 15, 17. [all data]

Radler and Berkowitz, 1977
Radler, K.; Berkowitz, J., Photoionization mass spectrometric study of CSe₂, J. Chem. Phys., 1977, 66, 2176. [all data]

Paule, 1976
Paule, R.C., Mass spectrometric studies of Al₂O₃ vaporization processes, High Temp. Sci., 1976, 8, 257. [all data]

Hildenbrand, 1975
Hildenbrand, D.L., Vertical ionization potential of the CF₂ radical, Chem. Phys. Lett., 1975, 32, 30. [all data]

Cermak, 1975
Cermak, V., Electron spectroscopy of autoionizing states of oxygen, chlorine and bromine atoms, J. Electron Spectrosc. Relat. Phenom., 1975, 6, 135. [all data]

Moore, 1970
Moore, C.E., Ionization potentials and ionization limits derived from the analyses of optical spectra, Natl. Stand. Ref. Data Ser., (U.S. Natl. Bur. Stand.), 1970, 34, 1. [all data]

Jonathan, Morris, et al., 1970
Jonathan, N.; Morris, A.; Smith, D.J.; Ross, K.J., Photoelectron spectra of ground state atomic hydrogen, nitrogen and oxygen, Chem. Phys. Lett., 1970, 7, 497. [all data]

Notes

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References

Symbols used in this document:

EA Electron affinity

IE (evaluated) Recommended ionization energy

Δ_rG° Free energy of reaction at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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EA	Electron affinity
IE (evaluated)	Recommended ionization energy
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions