Chlorine

Formula: Cl₂
Molecular weight: 70.906
IUPAC Standard InChI: InChI=1S/Cl2/c1-2
IUPAC Standard InChIKey: KZBUYRJDOAKODT-UHFFFAOYSA-N
CAS Registry Number: 7782-50-5
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: Cl2; Bertholite; Chloor; Chlor; Chlore; Chlorine mol.; Cloro; Molecular chlorine; UN 1017; Diatomic chlorine
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Gas phase ion energetics data

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Data compiled as indicated in comments:
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
B - John E. Bartmess

View reactions leading to Cl₂⁺ (ion structure unspecified)

Electron affinity determinations

EA (eV)	Method	Reference	Comment
2.50 ± 0.20	NBIE	Bowen, Liesegang, et al., 1983	B
2.33004	ECD	Ayala, Wentworth, et al., 1981	Vertical Detachment Energy: 1.02 eV; B
2.40 ± 0.20	NBIE	Dispert and Lacmann, 1977	B
2.32 ± 0.10	Endo	Hughes, Lifschitz, et al., 1973	B
2.45 ± 0.15	NBIE	Baeda, 1972	B
2.46 ± 0.14	IMRB	Dunkin, Fehsenfeld, et al., 1972	B
2.38 ± 0.10	Endo	Chupka, Berkowitz, et al., 1971	B
2.52 ± 0.17	EIAE	DeCorpo and Franklin, 1971	From CCl₄; B
1.020 ± 0.050	NBIE	Hubers, Kleyn, et al., 1976	Stated electron affinity is the Vertical Detachment Energy; B
3.20 ± 0.20	NBIE	Lacmann and Herschbach, 1970	B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
11.481 ± 0.003	TE	Yencha, Hopkirk, et al., 1995	LL
11.480 ± 0.005	PE	Van Lonkhuyzen and De Lange, 1984	LBLHLM
11.50	EVAL	Huber and Herzberg, 1979	LLK
11.51 ± 0.01	PE	Potts and Price, 1971	LLK
11.48 ± 0.01	PI	Dibeler, Walker, et al., 1971	LLK
11.49	PE	Cornford, Frost, et al., 1971	LLK
11.49	PE	Anderson, Mamantov, et al., 1971	LLK
11.48 ± 0.01	PI	Watanabe, 1957	RDSH
11.49	PE	Dyke, Josland, et al., 1984	Vertical value; LBLHLM
11.59	PE	Kimura, Katsumata, et al., 1981	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
Cl⁺	11.86 ± 0.04	Cl^-	EI	Frost and McDowell, 1959	RDSH

References

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

Bowen, Liesegang, et al., 1983
Bowen, K.H.; Liesegang, G.W.; Sanders, R.A.; Herschbach, D.W., Electron Attachment to Molecular Clusters by Collisional Charge Transfer, J. Phys. Chem., 1983, 87, 4, 557-565, https://doi.org/10.1021/j100227a009 . [all data]

Ayala, Wentworth, et al., 1981
Ayala, J.A.; Wentworth, W.E.; Chen, E.C.M., Electron attachment to halogens, J. Phys. Chem., 1981, 85, 768. [all data]

Dispert and Lacmann, 1977
Dispert, H.; Lacmann, K., Chemiionization in alkali-halogen reactions: Evidence for ion formation by alkali dimers, Chem. Phys. Lett., 1977, 47, 533. [all data]

Hughes, Lifschitz, et al., 1973
Hughes, B.M.; Lifschitz, C.; Tiernan, T.O., Electron affinities from endothermic negative-ion charge-transfer reactions. III. NO, NO₂, S₂, CS₂, Cl₂, Br₂, I₂, and C₂H, J. Chem. Phys., 1973, 59, 3162. [all data]

Baeda, 1972
Baeda, A.P.M., The adiabatic electron affinities of Cl₂, Br₂, I₂, IBr, NO₂, and O₂, Physica, 1972, 59, 541. [all data]

Dunkin, Fehsenfeld, et al., 1972
Dunkin, D.B.; Fehsenfeld, F.C.; Ferguson, F.E., Thermal energy rate constants for the reactions NO₂^- + Cl₂ → Cl₂^-, Cl₂^- + NO₂ Ü Cl^-, HS^- + NO₂ Ü NO₂^-, HS^- + Cl₂ Ü Cl₂^-, and S^- + NO₂ Ü NO₂^-, Chem. Phys. Lett., 1972, 15, 257. [all data]

Chupka, Berkowitz, et al., 1971
Chupka, W.A.; Berkowitz, J.; Gutman, D., Electron Affinities of Halogen Diatomic Molecules as Determined by Endoergic Charge Exchange, J. Chem. Phys., 1971, 55, 6, 2724, https://doi.org/10.1063/1.1676487 . [all data]

DeCorpo and Franklin, 1971
DeCorpo, J.J.; Franklin, J.L., Electron affinities of the halogen molecules by dissociative electron attachment, J. Chem. Phys., 1971, 54, 1885. [all data]

Hubers, Kleyn, et al., 1976
Hubers, M.M.; Kleyn, A.W.; Los, J., Ion pair formation in alkali-halogen collisions at high velocities, Chem. Phys., 1976, 17, 303. [all data]

Lacmann and Herschbach, 1970
Lacmann, K.; Herschbach, D.R., Collisional Excitation and Ionization of K Atoms by Diatomic Molecules: Role of Ion-pair States, Chem. Phys. Lett., 1970, 6, 2, 106, https://doi.org/10.1016/0009-2614(70)80144-0 . [all data]

Yencha, Hopkirk, et al., 1995
Yencha, A.J.; Hopkirk, A.; Hiraya, A.; Donovan, R.J.; Goode, J.G.; Maier, R.R.J.; King, G.C.; Kvaran, A., Threshold photoelectron spectroscopy of Cl₂ and Br₂ up to 35 eV, J. Phys. Chem., 1995, 99, 7231. [all data]

Van Lonkhuyzen and De Lange, 1984
Van Lonkhuyzen, H.; De Lange, C.A., High-resolution UV photoelectron spectroscopy of diatomic halogens, Chem. Phys., 1984, 89, 313. [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979, ,1. [all data]

Potts and Price, 1971
Potts, A.W.; Price, W.C., Photoelectron spectra of the halogens and mixed halides ICI and lBr, J. Chem. Soc. Faraday Trans., 1971, 67, 1242. [all data]

Dibeler, Walker, et al., 1971
Dibeler, V.H.; Walker, J.A.; McCulloh, K.E.; Rosenstock, H.M., Effect of hot bands on the ionization threshold of some diatomic halogen molecules, Intern. J. Mass Spectrom. Ion Phys., 1971, 7, 209. [all data]

Cornford, Frost, et al., 1971
Cornford, A.B.; Frost, D.C.; McDowell, C.A.; Ragle, J.L.; Stenhouse, I.A., Photoelectron spectra of the halogens, J. Chem. Phys., 1971, 54, 2651. [all data]

Anderson, Mamantov, et al., 1971
Anderson, C.P.; Mamantov, G.; Bull, W.E.; Grimm, F.A.; Carver, J.C.; Carlson, T.A., Photoelectron spectrum of chlorine monofluoride, Chem. Phys. Lett., 1971, 12, 137. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Dyke, Josland, et al., 1984
Dyke, J.M.; Josland, G.D.; Snijders, J.G.; Boerrigter, P.M., Ionization energies of the diatomic halogens and interhalogens studied with relativistic hartree-fock-slater calculations, Chem. Phys., 1984, 91, 419. [all data]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Frost and McDowell, 1959
Frost, D.C.; McDowell, C.A., Recent electron impact studies on simple molecules (O₂, Cl₂, I₂), Advan. Mass Spectrom., 1959, 1, 413. [all data]

Notes

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

Symbols used in this document:

AE Appearance energy

EA Electron affinity
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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