Bromine

• Formula: Br₂
• Molecular weight: 159.808
• IUPAC Standard InChI: InChI=1S/Br2/c1-2 Copy

  
• IUPAC Standard InChIKey: GDTBXPJZTBHREO-UHFFFAOYSA-N Copy
• CAS Registry Number: 7726-95-6
• 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.
• Other names: Br2; Brom; Brome; Bromo; Broom; UN 1744; Dibromine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase ion energetics data
  • Ion clustering data
  • Mass spectrum (electron ionization)
  • Constants of diatomic molecules
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 55
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Gas phase ion energetics data

Go To: Top, Ion clustering data, Mass spectrum (electron ionization), Constants of diatomic molecules, 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:
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 Br₂⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

Anion protonation reactions

 +  =

By formula: Br^- + H⁺ = HBr

Ion clustering data

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), Constants of diatomic molecules, 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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

 +  = ( • )

By formula: Br^- + Br₂ = (Br^- • Br₂)

Br₃^- +  = (Br₃^- • )

By formula: Br₃^- + Br₂ = (Br₃^- • Br₂)

Mass spectrum (electron ionization)

Go To: Top, Gas phase ion energetics data, Ion clustering data, Constants of diatomic molecules, 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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

Constants of diatomic molecules

Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), 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: Klaus P. Huber and Gerhard H. Herzberg

Data collected through September, 1976

Notes

References

Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Constants of diatomic molecules, Notes

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

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]

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]

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]

Ruscic and Berkowitz, 1994
Ruscic, B.; Berkowitz, J., Threshold photoelectron spectrum of HOBr, J. Chem. Phys., 1994, 101, 9215. [all data]

Monks, Stief, et al., 1994
Monks, P.S.; Stief, L.J.; Krauss, M.; Kuo, S.C.; Klemm, R.B., A discharge flow-photoionization mass spectrometric study of HOBr (X<1>A'): Photoion yield spectrum, ionization energy, and thermochemistry, J. Chem. Phys., 1994, 100, 1902. [all data]

Lau and Hildenbrand, 1987
Lau, K.H.; Hildenbrand, D.L., Thermochemistry of the gaseous uranium bromides UBr through UBr₅(a), J. Chem. Phys., 1987, 86, 2949. [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]

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]

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]

Kaposi, Popovic, et al., 1977
Kaposi, O.; Popovic, A.; Marsel, J., Mass spectrometric studies of tungsten bromides and oxybromides, J. Inorg. Nucl. Chem., 1977, 39, 1809. [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]

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]

Dibeler, Walker, et al., 1970
Dibeler, V.H.; Walker, J.A.; McCulloh, K.E., Threshold for molecular photoionization of bromine, J. Chem. Phys., 1970, 53, 4715. [all data]

Venkateswarlu, 1968
Venkateswarlu, P., Vacuum ultraviolet spectrum of bromine molecule, Bull. Am. Phys. Soc., 1968, 13, 1666. [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]

Utsunomiya, Kobayashi, et al., 1976
Utsunomiya, C.; Kobayashi, T.; Nagakura, S., Photoelectron spectra of electron donor-acceptor complexes between bromine and alkylamines, Chem. Phys. Lett., 1976, 39, 245. [all data]

Morrison, Hurzeler, et al., 1960
Morrison, J.D.; Hurzeler, H.; Inghram, M.G.; Stanton, H.E., Threshold law for the probability of excitation of molecules by photon impact. A study of the photoionization efficiencies of Br₂, I₂, HI, and CH₃I, J. Chem. Phys., 1960, 33, 821. [all data]

Frost and McDowell, 1960
Frost, D.C.; McDowell, C.A., The ionization and dissociation of some halogen molecules by electron impact, Can. J. Chem., 1960, 38, 407. [all data]

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

Blondel, Cacciani, et al., 1989
Blondel, C.; Cacciani, P.; Delsart, C.; Trainham, R., High Resolution Determination of the Electron Affinity of Fluorine and Bromine using Crossed Ion and Laser Beams, Phys. Rev. A, 1989, 40, 7, 3698, https://doi.org/10.1103/PhysRevA.40.3698 . [all data]

Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G., Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase, Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005 . [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]

Nizzi, Pommerening, et al., 1998
Nizzi, K.E.; Pommerening, C.A.; Sunderlin, L.S., Gas-phase thermochemistry of polyhalide anions, J. Phys. Chem. A, 1998, 102, 39, 7674-7679, https://doi.org/10.1021/jp9824508 . [all data]

Venkateswarlu, 1947
Venkateswarlu, P., Emission bands of halogens. Part IV. Diffuse bands of bromine, Proc. Indian Acad. Sci. Sect. A, 1947, 25, 138. [all data]

Venkateswarlu, 1969
Venkateswarlu, P., The vacuum ultraviolet spectrum of the bromine molecule, Can. J. Phys., 1969, 47, 2525. [all data]

Haranath and Rao, 1958
Haranath, P.B.V.; Rao, P.T., Band spectra of iodine, chlorine, and bromine in the spectral region 2400-1400 A, J. Mol. Spectrosc., 1958, 2, 428. [all data]

Rao and Venkateswarlu, 1964
Rao, Y.V.; Venkateswarlu, P., Vacuum ultraviolet resonance spectrum of Br₂ molecule, J. Mol. Spectrosc., 1964, 13, 288. [all data]

Verma, 1958
Verma, R.D., Emission spectrum of bromine excited in the presence of argon. Part III. The band system in the region 2660-2590 Å, Proc. Indian Acad. Sci. Sect. A, 1958, 47, 196. [all data]

Venkateswarlu and Verma, 1958
Venkateswarlu, P.; Verma, R.D., Emission spectrum of bromine excited in the presence of argon-Part I, Proc. Indian Acad. Sci. Sect. A, 1958, 46, 251. [all data]

Wieland, Tellinghuisen, et al., 1972
Wieland, K.; Tellinghuisen, J.B.; Nobs, A., The band systems E → B(4000-4360 Å) and F → X(2530-2740 Å) of ¹²⁷I₂ and ¹²⁹I₂, and the corresponding system E = B of Br₂ and Cl₂, J. Mol. Spectrosc., 1972, 41, 69. [all data]

Venkateswarlu and Verma, 1958, 2
Venkateswarlu, P.; Verma, R.D., Emission spectrum of bromine excited in the presence of argon. Part II. The band system in the region 3150-2970 Å, Proc. Indian Acad. Sci. Sect. A, 1958, 46, 416. [all data]

Cordes and Sponer, 1930
Cordes, H.; Sponer, H., Die molekulabsorption des chlors, broms, jodchlorids und jodbromids im aubersten ultraviolett, Z. Phys., 1930, 63, 334. [all data]

Aickin and Bayliss, 1938
Aickin, R.G.; Bayliss, N.S., The absorption spectrum of bromine vapour in the region 3400 A to 2200 A, Trans. Faraday Soc., 1938, 34, 1371. [all data]

Mulliken, 1940
Mulliken, R.S., Halogen molecule spectra. II. Interval relations and relative intensities in the long wave-length spectra, Phys. Rev., 1940, 57, 500. [all data]

Rees, 1947
Rees, A.L.G., Note on the interpretation of the visible absorption spectrum of bromine, Proc. Phys. Soc. London, 1947, 59, 1008. [all data]

Bayliss and Sullivan, 1954
Bayliss, N.S.; Sullivan, J.V., Vacuum ultraviolet absorption spectra of iodine and bromine, J. Chem. Phys., 1954, 22, 1615. [all data]

Coxon, 1973
Coxon, J.A., Chapt. 4. Low-lying electronic states of diatomic halogen molecules in Molecular Spectroscopy. Volume 1, Barrow,R.F.; Long,D.A.; Millen,D.J., ed(s)., The Chemical Society, Burlington House, London, W1V 0BN, 1973, 177-228. [all data]

Holzer, Murphy, et al., 1970
Holzer, W.; Murphy, W.F.; Bernstein, H.J., Resonance fluorescence of iodine, bromine, and chlorine gases obtained with argon-ion laser excitation, J. Chem. Phys., 1970, 52, 469. [all data]

Barrow, Clark, et al., 1974
Barrow, R.F.; Clark, T.C.; Coxon, J.A.; Yee, K.K., The B³Π_0u+ - X¹Σ_g⁺ system of Br₂ rotational analysis, Franck-Condon factors, and long range potential in the B_0u+ state, J. Mol. Spectrosc., 1974, 51, 428. [all data]

Ault, Howard, et al., 1975
Ault, B.S.; Howard, W.F.; Andrews, L., Laser-induced fluorescence and Raman spectra of chlorine and bromine molecules isolated in inert matrices, J. Mol. Spectrosc., 1975, 55, 217. [all data]

Horsley, 1967
Horsley, J.A., Rotational analysis of the A³Π_1u - X¹Σ_g⁺ system of bromine, J. Mol. Spectrosc., 1967, 22, 469. [all data]

Coxon, 1972
Coxon, J.A., The extreme red absorption spectrum of Br₂, A³Π(1_u) ← X¹Σ_g⁺, J. Mol. Spectrosc., 1972, 41, 548. [all data]

Briggs and Norrish, 1963
Briggs, A.G.; Norrish, R.G.W., Transient absorption spectra of chlorine and bromine, Proc. R. Soc. London A, 1963, 276, 51. [all data]

Brith, Rowe, et al., 1975
Brith, M.; Rowe, M.D.; Schnepp, O.; Stephens, P.J., The magnetic circular dichroism spectrum of the halogen molecules I₂, Br₂, Cl₂. Resolution of overlapping continua, Chem. Phys., 1975, 9, 57. [all data]

Oldman, Sander, et al., 1975
Oldman, R.J.; Sander, R.K.; Wilson, K.R., Photofragment spectrum of bromine, J. Chem. Phys., 1975, 63, 4252. [all data]

Bondybey, Bearder, et al., 1976
Bondybey, V.E.; Bearder, S.S.; Fletcher, C., Br₂B³Π(0_u⁺) excitation spectra and radiative lifetimes in rare gas solids, J. Chem. Phys., 1976, 64, 5243. [all data]

Eng and LaTourrette, 1974
Eng, R.S.; LaTourrette, J.T., Hyperfine spectra of bromine vapor near 633 nm, J. Mol. Spectrosc., 1974, 52, 269. [all data]

Lum and McAfee, 1975
Lum, R.M.; McAfee, K.B., Jr., Direct measurement of spontaneous predissociation using coaxial laser-molecular beams, J. Chem. Phys., 1975, 63, 5029. [all data]

Lum and Hozack, 1975
Lum, R.M.; Hozack, R.S., Identification of selectively excited transitions in Br₂ isotopes at 5145 Å, J. Mol. Spectrosc., 1975, 58, 325-327. [all data]

Clyne, Coxon, et al., 1971
Clyne, M.A.A.; Coxon, J.A.; Woon-Fat, A.R., Electronic excitation of bromine to the B³Π(0_u⁺) state in the recombination of ground state Br²P_2/3 atoms, Trans. Faraday Soc., 1971, 67, 3155. [all data]

Coxon, 1971
Coxon, J.A., The calculation of potential energy curves of diatomic molecules: application to halogen molecules, J. Quant. Spectrosc. Radiat. Transfer, 1971, 11, 443. [all data]

Goscinski, 1972
Goscinski, O., Outer vibrational turning points near dissociation in the B(³Π_0u⁺) state of Br₂ and Cl₂, Mol. Phys., 1972, 24, 655. [all data]

Yee and Stone, 1973
Yee, K.K.; Stone, T.J., Analysis of RKR long-range potentials of the B³Π_0u+ states of Br₂ and Cl₂, Mol. Phys., 1973, 26, 1169. [all data]

LeRoy, 1974
LeRoy, R.J., Long-range potential coefficients from RKR turning points: C₆ and C₈ for B(³Π_0u⁺)-state Cl₂, Br₂, and I₂, Can. J. Phys., 1974, 52, 246. [all data]

Capelle, Sakurai, et al., 1971
Capelle, G.; Sakurai, K.; Broida, H.P., Lifetimes and self-quenching cross sections of cibrational levels in the B state of bromine excited by a tunable dye laser, J. Chem. Phys., 1971, 54, 1728. [all data]

McAfee and Hozack, 1976
McAfee, K.B., Jr.; Hozack, R.S., Lifetimes and energy transfer near the dissociation limit in bromine, J. Chem. Phys., 1976, 64, 2491. [all data]

Sulzmann, Bien, et al., 1967
Sulzmann, K.G.P.; Bien, F.; Penner, S.S., Intensity and collision half-width measurements using a laser source. II. Continuum and line absorption of Br₂ at 6328 A, J. Quant. Spectrosc. Radiat. Transfer, 1967, 7, 969. [all data]

Clyne and Coxon, 1967
Clyne, M.A.A.; Coxon, J.A., The emission spectra of Br₂ and IBr formed in atomic recombination processes, J. Mol. Spectrosc., 1967, 23, 258. [all data]

Frost, McDowell, et al., 1967
Frost, D.C.; McDowell, C.A.; Vroom, D.A., Photoelectron spectra of the halogens and the hydrogen halides, J. Chem. Phys., 1967, 46, 4255. [all data]

Holzer, Murphy, et al., 1970, 2
Holzer, W.; Murphy, W.F.; Bernstein, H.J., Resonance Raman effect and resonance fluoroscence in halogen gases, J. Chem. Phys., 1970, 52, 399. [all data]

Baierl and Kiefer, 1975
Baierl, P.; Kiefer, W., Hot band and isotopic structure in the resonance Raman spectrum of bromine vapor, J. Chem. Phys., 1975, 62, 306. [all data]

Baierl, Hochenbleicher, et al., 1975
Baierl, P.; Hochenbleicher, J.G.; Kiefer, W., Pure rotational Raman spectra of ⁷⁹Br₂ and ⁸¹Br₂, Appl. Spectrosc., 1975, 29, 356. [all data]

Notes

Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Constants of diatomic molecules, References

• Symbols used in this document:
  

  AE	Appearance energy
  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
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