Chlorine atom

• Formula: Cl
• Molecular weight: 35.453
• IUPAC Standard InChI: InChI=1S/Cl Copy

  
• IUPAC Standard InChIKey: ZAMOUSCENKQFHK-UHFFFAOYSA-N Copy
• CAS Registry Number: 22537-15-1
• Chemical structure:
  This structure is also available as a 2d Mol file
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Ion clustering data
• Data at other public NIST sites:
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  • NIST Atomic Spectra Database - Levels Holdings (on physics web site)
  • NIST Atomic Spectra Database - Ground states and ionization energies (on physics web site)
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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 (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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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:
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 Cl⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Anion protonation reactions

 +  =

By formula: Cl^- + H⁺ = HCl

References

Go To: Top, Gas phase 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.

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

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

Martin and Hepburn, 1998
Martin, J.D.D.; Hepburn, J.W., Determination of bond dissociation energies by threshold ion-pair production spectroscopy: An improved D-0(HCl), J. Chem. Phys., 1998, 109, 19, 8139-8142, https://doi.org/10.1063/1.477476 . [all data]

Trainham, Fletcher, et al., 1987
Trainham, R.; Fletcher, G.D.; Larson, D.J., One- and Two-Photon Detachment of the Negative Chlorine Ion, J. Phys. B: Atom. Mol. Phys., 1987, 20, 23, L777, https://doi.org/10.1088/0022-3700/20/23/002 . [all data]

Berzinsh, Gustafsson, et al., 1995
Berzinsh, U.; Gustafsson, M.; Hanstorp, D.; Klinkmuller, A.; Ljungblad, U.; Martenssonpendrill, A.M., Isotope shift in the electron affinity of chlorine, Phys. Rev. A, 1995, 51, 1, 231, https://doi.org/10.1103/PhysRevA.51.231 . [all data]

Berry and Reimann, 1963
Berry, R.S.; Reimann, C.W., Absorption Spectrum of Gaseous Fluoride and the Electron Affinities of the Halogen Atoms, J. Chem. Phys., 1963, 38, 7, 1540, https://doi.org/10.1063/1.1776916 . [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]

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]

Kimura, Yamazaki, et al., 1978
Kimura, K.; Yamazaki, T.; Achiba, Y., He I (584 A) photoelectron spectra and photoionization cross sections of atomic chlorine and bromine, Chem. Phys. Lett., 1978, 58, 104. [all data]

De Leeuw, Mooyman, et al., 1978
De Leeuw, D.M.; Mooyman, R.; De Lange, C.A., He(I) photoelectron spectroscopy of halogen atoms, Chem. Phys. Lett., 1978, 54, 231. [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]

Radziemski and Kaufman, 1969
Radziemski, L.J., Jr.; Kaufman, V., Wavelengths, energy levels, and analysis of neutral atomic chlorine (Cl I), J. Opt. Soc. Am., 1969, 59, 424. [all data]

Fujio, McIver, et al., 1981
Fujio, M.; McIver, R.T., Jr.; Taft, R.W., Effects on the acidities of phenols from specific substituent-solvent interactions. Inherent substituent parameters from gas phase acidities, J. Am. Chem. Soc., 1981, 103, 4017. [all data]

Notes

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• 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)
  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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