Dichlorine monoxide

• Formula: Cl₂O
• Molecular weight: 86.905
• IUPAC Standard InChI: InChI=1S/Cl2O/c1-3-2 Copy

  
• IUPAC Standard InChIKey: RCJVRSBWZCNNQT-UHFFFAOYSA-N Copy
• CAS Registry Number: 7791-21-1
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Other names: Chlorine oxide (Cl2O); Chlorine monooxide; Dichloromonoxide; Chlorine monoxide; Chlorine monoxide (Cl2O); Dichloroxide; Hypochlorous anhydride; Cl2O; Chlorine oxide; Dichlorine oxide
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Henry's Law data
  • Mass spectrum (electron ionization)
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Computational Chemistry Comparison and Benchmark Database
  • Gas Phase Kinetics Database
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Gas phase 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.

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 (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Phase change 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.

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (atm)
    T = temperature (K)

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Gas phase ion energetics 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 evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

References

Go To: Top, Gas 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.

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

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Wecker, Christodoulides, et al., 1981
Wecker, D.; Christodoulides, A.A.; Schnidler, R.N., Studies by the Electron Cyclotron Resonance (ECR) Technique. XV. Interactions of Thermal-Energy Electrons with ClO₂ and Cl₂O, Int. J. Mass Spectrom. Ion Phys., 1981, 38, 2-3, 291, https://doi.org/10.1016/0020-7381(81)80084-8 . [all data]

Thorn, Stief, et al., 1996
Thorn, R.P., Jr.; Stief, L.J.; Kuo, S.-C.; Klemm, R.B., Ionization energy of Cl₂O and ClO, appearance energy of ClO⁺(Cl₂O), and heat of formation of Cl₂O, J. Phys. Chem., 1996, 100, 14178. [all data]

Cornford, Frost, et al., 1971
Cornford, A.B.; Frost, D.C.; Herring, F.G.; McDowell, C.A., Photoelectron spectra of F₂O and Cl₂O, J. Chem. Phys., 1971, 55, 2820. [all data]

Fisher, 1968
Fisher, I.P., Intermediates in the pyrolysis and mass spectrometry of chlorine monoxide and chlorine heptoxide, J. Chem. Soc. Faraday Trans., 1968, 64, 1852. [all data]

Chadwick, Cornford, et al., 1972
Chadwick, D.; Cornford, A.B.; Frost, D.C.; Herring, F.G.; Katrib, A.; McDowell, C.A.; McLean, R.A.N., Photoelectron spectra of some dihalocompounds in Electron spectroscopy, ed. D.A. Shirley (North-Holland Publixhing Co, Amsterdam), 1972, 453. [all data]

Notes

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• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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