Hydroperoxy radical

• Formula: HO₂
• Molecular weight: 33.0067
• IUPAC Standard InChI: InChI=1S/HO2/c1-2/h1H Copy

  
• IUPAC Standard InChIKey: OUUQCZGPVNCOIJ-UHFFFAOYSA-N Copy
• CAS Registry Number: 3170-83-0
• 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.
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Henry's Law data
  • Vibrational and/or electronic energy levels
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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.

Reaction thermochemistry data

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: 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

 +  =

By formula: O₂^- + H⁺ = HO₂

Gas phase ion energetics data

Go To: Top, Reaction thermochemistry data, 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
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 HO₂⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

De-protonation reactions

 +  =

By formula: O₂^- + H⁺ = HO₂

References

Go To: Top, Reaction thermochemistry 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.

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]

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]

Ramond, Blanksby, et al., 2002
Ramond, T.M.; Blanksby, S.J.; Kato, S.; Bierbaum, V.M.; Davico, G.E.; Schwartz, R.L.; Lineberger, W.C.; Elliso, Heat of formation of the hydroperoxyl radical HOO via negative ion studies, J. Phys. Chem. A, 2002, 106, 42, 9641-9647, https://doi.org/10.1021/jp014614h . [all data]

Clifford, Wenthold, et al., 1998
Clifford, E.P.; Wenthold, P.G.; Gareyev, R.; Lineberger, W.C.; DePuy, C.H.; Bierbaum, V.M.; Ellison, G.B., Photoelectron spectroscopy, gas phase acidity, and thermochemistry of tert-butyl hydroperoxide: Mechanisms for the rearrangement of peroxyl radicals, J. Chem. Phys., 1998, 109, 23, 10293-10310, https://doi.org/10.1063/1.477725 . [all data]

Oakes, Harding, et al., 1985
Oakes, J.M.; Harding, L.B.; Ellison, G.B., The photoelectron spectroscopy of HO₂^-, J. Chem. Phys., 1985, 83, 5400. [all data]

Bierbaum, Schmidt, et al., 1981
Bierbaum, V.M.; Schmidt, R.J.; DePuy, C.H.; Mead, R.H.; Schulz, P.A.; Lineberger, W.C., Reactions of carbanions with triplet and singlet molecular oxygen, J. Am. Chem. Soc., 1981, 103, 6262. [all data]

Benson and Nangia, 1980
Benson, S.W.; Nangia, P.S., Electron affinity of HO₂. and HO_x radicals, J. Am. Chem. Soc., 1980, 102, 2843. [all data]

Dyke, Jonathan, et al., 1981
Dyke, J.M.; Jonathan, N.B.H.; Morris, A.; Winter, M., Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 13. Observation of the X3A state of HO₂, Mol. Phys., 1981, 44, 1059. [all data]

Tal'roze, Butkovskaya, et al., 1978
Tal'roze, V.L.; Butkovskaya, N.I.; Larichev, M.N.; Leipunskii, I.O.; Morozov, I.I.; Dodonov, A.F.; Kudrov, B.V.; Zelenov, V.V.; Raznikov, V.V., Advances in the mass spectrometry of free radicals, Adv. Mass Spectrom., 1978, 7, 693. [all data]

Foner and Hudson, 1955
Foner, S.N.; Hudson, R.L., Ionization potential of the free HO₂ radical and the H-O₂ bond dissociation energy, J. Chem. Phys., 1955, 23, 1364. [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
  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
• 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.