Hydroxyl radical

• Formula: HO
• Molecular weight: 17.0073
• IUPAC Standard InChI: InChI=1S/HO/h1H Copy

  
• IUPAC Standard InChIKey: TUJKJAMUKRIRHC-UHFFFAOYSA-N Copy
• CAS Registry Number: 3352-57-6
• 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.
• Isotopologues:
  • Hydroxyl-d
  • hydroxyl-t
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • References
  • Notes
• Other data available:
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Computational Chemistry Comparison and Benchmark Database
  • 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)

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Gas phase thermochemistry data

Go To: Top, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Ion clustering data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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View table.

Reaction 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: 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

O^- +  =

By formula: O^- + H⁺ = HO

 +  = HFO^-

By formula: F^- + HO = HFO^-

 +  = ( • )

By formula: H^- + HO = (H^- • HO)

Henry's Law 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: Rolf Sander

Henry's Law constant (water solution)

k_H(T) = k°_H exp(d(ln(k_H))/d(1/T) ((1/T) - 1/(298.15 K)))
k°_H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(k_H))/d(1/T) = Temperature dependence constant (K)

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Henry's Law data, Ion clustering 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
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 HO⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

De-protonation reactions

O^- +  =

By formula: O^- + H⁺ = HO

Ion clustering 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: John E. Bartmess

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

 +  = HFO^-

By formula: F^- + HO = HFO^-

 +  = ( • )

By formula: H^- + HO = (H^- • HO)

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Ion clustering data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [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]

Deyerl and Continetti, 2005
Deyerl, H.J.; Continetti, R.E., Photoelectron-photofragment coincidence study of OHF-: transition state dynamics of the reaction OH+F - O+HF, Phys. Chem. Chem. Phys., 2005, 7, 5, 855-860, https://doi.org/10.1039/b414604b . [all data]

de Koening and Nibbering, 1984
de Koening, L.J.; Nibbering, N.M.M., Formation of the Long-Lived H₂O^-. Ion in the Gas Phase, J. Am. Chem. Soc., 1984, 106, 25, 7971, https://doi.org/10.1021/ja00337a054 . [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]

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]

Celotta, Bennett, et al., 1974
Celotta, R.S.; Bennett, R.A.; Hall, J.L., Laser Photodetachment Determination of the Electron Affinities of OH, NH₂, NH, SO₂, and S₂, J. Chem. Phys., 1974, 60, 5, 1740, https://doi.org/10.1063/1.1681268 . [all data]

Hotop, Patterson, et al., 1974
Hotop, H.; Patterson, T.A.; Lineberger, W.C., High resolution photodetachment study of OH- and OD- in the threshold region 7000-6450 Å, J. Chem. Phys., 1974, 60, 1806. [all data]

Branscomb, 1966
Branscomb, L.M., Photodetachment Cross Section, Electron Affinity, and Structure of the Negative Hydroxyl Ion, Phys. Rev., 1966, 148, 1, 11, https://doi.org/10.1103/PhysRev.148.11 . [all data]

Tsuda and Hamill, 1964
Tsuda, S.; Hamill, W.H., Ionization Efficiency Measurements by the Retarding Potential Difference Method, Adv. Mass Spectrom., 1964, 3, 249. [all data]

Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S., Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements, J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l . [all data]

Page and Goode, 1969
Page, F.M.; Goode, G.C., Negative Ions and the Magnetron., Wiley, NY, 1969. [all data]

Wiedmann, Tonkyn, et al., 1992
Wiedmann, R.T.; Tonkyn, R.G.; White, M.G.; Wang, K.; McKoy, V., Rotationally resolved threshold photoelectron spectra of OH and OD, J. Chem. Phys., 1992, 97, 768. [all data]

Van Lonkhuyzen and De Lange, 1984
Van Lonkhuyzen, H.; De Lange, C.A., U. V. photoelectron spectroscopy of OH and OD radicals, Mol. Phys., 1984, 51, 551. [all data]

Berkowitz, Appelman, et al., 1973
Berkowitz, J.; Appelman, E.H.; Chupka, W.A., Photoionization of HOF with mass analysis, J. Chem. Phys., 1973, 58, 1950. [all data]

Uy, Srivastava, et al., 1971
Uy, O.M.; Srivastava, R.D.; Farber, M., Mass spectrometric determination of the heats of formation of gaseous BO₂ BOF₂, High Temp. Sci., 1971, 3, 462. [all data]

Dibeler, Walker, et al., 1966
Dibeler, V.H.; Walker, J.A.; Rosenstock, H.M., Mass spectrometric study of photoionization. V.Water and ammonia, J.Res. NBS, 1966, 70A, 459. [all data]

Foner and Hudson, 1956
Foner, S.N.; Hudson, R.L., Ionization potential of the OH free radical by mass spectrometry, J. Chem. Phys., 1956, 25, 602. [all data]

Katsumata and Lloyd, 1977
Katsumata, S.; Lloyd, D.R., The photoelectron spectra of the OH and OD radicals, Chem. Phys. Lett., 1977, 45, 519. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Ion clustering data, References

• Symbols used in this document:
  

  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  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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