Benzyne

• Formula: C₆H₄
• Molecular weight: 76.0960
• IUPAC Standard InChI: InChI=1S/C6H4/c1-2-4-6-5-3-1/h1-4H Copy

  
• IUPAC Standard InChIKey: KLYCPFXDDDMZNQ-UHFFFAOYSA-N Copy
• CAS Registry Number: 462-80-6
• 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.
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• Information on this page:
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
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Reaction thermochemistry data

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, 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. 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

 +  =

By formula: C₆H₃^- + H⁺ = C₆H₄

(CAS Reg. No. 72863-53-7 • 4294967295) +  = CAS Reg. No. 72863-53-7

By formula: (CAS Reg. No. 72863-53-7 • 4294967295C₆H₄) + C₆H₄ = CAS Reg. No. 72863-53-7

(CAS Reg. No. 77748-26-6 • 4294967295) +  = CAS Reg. No. 77748-26-6

By formula: (CAS Reg. No. 77748-26-6 • 4294967295C₆H₄) + C₆H₄ = CAS Reg. No. 77748-26-6

Gas phase ion energetics data

Go To: Top, Reaction thermochemistry data, Vibrational and/or electronic energy levels, 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

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 C₆H₄⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

De-protonation reactions

 +  =

By formula: C₆H₃^- + H⁺ = C₆H₄

Vibrational and/or electronic energy levels

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, 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: Marilyn E. Jacox

State:   ?

State:   ?

State:   ?

State:   ?

State:   a

State:   X

Additional references: Jacox, 1994, page 386; Jacox, 2003, page 364; Brown, Godfrey, et al., 1986; Robertson, Godfrey, et al., 2003; Kukolich, Tanjaroon, et al., 2003; Kukolich, McCarthy, et al., 2004

Notes

References

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, Notes

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

Guo and Grabowski, 1991
Guo, Y.L.; Grabowski, J.J., Reactions of the Benzyne Radical Anion in the Gas Phase, the Acidity of the Phenyl Radical, and the Heat of Formation of ortho-Benzyne, J. Am. Chem. Soc., 1991, 113, 16, 5923, https://doi.org/10.1021/ja00016a001 . [all data]

Gronert and DePuy, 1989
Gronert, S.; DePuy, C.H., The Dehydrophenyl Anion and the Gas Phase Ion Chemistry of Benzyne, J. Am. Chem. Soc., 1989, 111, 26, 9253, https://doi.org/10.1021/ja00208a032 . [all data]

Andrade and Riveros, 1996
Andrade, P.B.M.; Riveros, J.M., Relative Gas-phase Acidities of Fluoro- and Chlorobenzene, J. Mass Spectrom., 1996, 31, 7, 767, https://doi.org/10.1002/(SICI)1096-9888(199607)31:7<767::AID-JMS345>3.0.CO;2-Q . [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R., Determination of the gas-phase acidities of halogen-substituted aromatic compounds using the silane-cleavage method, J. Mass Spectrom., 1995, 30, 1, 17, https://doi.org/10.1002/jms.1190300105 . [all data]

Wenthold, Paulino, et al., 1991
Wenthold, P.G.; Paulino, J.A.; Squires, R.R., The Absolute Heats of Formation of ortho-Benzyne, meta-Benzyne, and para-Benzyne, J. Am. Chem. Soc., 1991, 113, 19, 7414, https://doi.org/10.1021/ja00019a044 . [all data]

Meot-ner and Kafafi, 1988
Meot-ner, M.; Kafafi, S.A., Carbon Acidities of Aromatic Compounds, J. Am. Chem. Soc., 1988, 110, 19, 6297, https://doi.org/10.1021/ja00227a003 . [all data]

Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B., Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine, J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z . [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]

Wenthold, Squires, et al., 1998
Wenthold, P.G.; Squires, R.R.; Lineberger, W.C., Ultraviolet photoelectron spectroscopy of the o-, m-, and p-benzyne negative ions. Electron affinities and singlet-triplet splittings for o-, m-, and p-benzyne, J. Am. Chem. Soc., 1998, 120, 21, 5279-5290, https://doi.org/10.1021/ja9803355 . [all data]

Wenthold, Hu, et al., 1996
Wenthold, P.G.; Hu, J.; Squires, R.R., o-, m-, and p-Benzyne Negative Ions in the Gas Phase: Synthesis, Authentication, and Thermochemistry, J. Am. Chem. Soc., 1996, 118, 47, 11865, https://doi.org/10.1021/ja960663+ . [all data]

Leopold, Miller, et al., 1986
Leopold, D.G.; Miller, A.G.; Lineberger, W.C., Determination of the singlet-triplet splitting and electron affinity of, o-benzyne by negative ion photoelectron spectroscopy, J. Am. Chem. Soc., 1986, 108, 1379. [all data]

Zhang and Chen, 1992
Zhang, X.; Chen, P., Photoelectron spectrum of o-benzyne. Ionization potentials as a measure of singlet-triplet gaps, J. Am. Chem. Soc., 1992, 114, 3147. [all data]

Dewar and Tien, 1985
Dewar, M.J.S.; Tien, T.-P., Photoelectron spectrum of benzyne, J. Chem. Soc., Chem. Commun., 1985, 1243. [all data]

Rosenstock, Stockbauer, et al., 1980
Rosenstock, H.M.; Stockbauer, R.; Parr, A.C., Photoelectron-photoion coincidence study of benzonitrile, J. Chim. Phys., 1980, 77, 745. [all data]

Grutzmacher and Hubner, 1969
Grutzmacher, H.-F.; Hubner, J., Massenspektrometrie instabiler molekule. III: Nachweis und untersuchungen zur stabilitat chlorsubstituierter dehydrobenzole in der gasphase, Org. Mass Spectrom., 1969, 2, 649. [all data]

Grutzmacher and Lohmann, 1967
Grutzmacher, H.-F.; Lohmann, J., Massenspektrometrie instabiler organischer Molekule. I. Ionisations-potential und Bildungsenthalpie von Dehydrobenzol, Ann. Chem., 1967, 705, 81. [all data]

Munzel and Schweig, 1988
Munzel, N.; Schweig, A., UV/VIS absorption spectrum, geometry and electronic structure of transient o-benzyne, Chem. Phys. Lett., 1988, 147, 2-3, 192, https://doi.org/10.1016/0009-2614(88)85082-6 . [all data]

Simon, Munzel, et al., 1990
Simon, J.G.G.; Munzel, N.; Schweig, A., Matrix isolation photochemistry: photoequilibrium between transient o-benzyne, carbon monoxide and transient cyclopentadienylideneketene in an argon matrix, Chem. Phys. Lett., 1990, 170, 2-3, 187, https://doi.org/10.1016/0009-2614(90)87113-6 . [all data]

Radziszewski, Hess, et al., 1992
Radziszewski, J.G.; Hess, B.A., Jr.; Zahradnik, R., Infrared spectrum of o-benzyne: experiment and theory, J. Am. Chem. Soc., 1992, 114, 1, 52, https://doi.org/10.1021/ja00027a007 . [all data]

Leopold, Stevens-Miller, et al., 1986
Leopold, D.G.; Stevens-Miller, A.E.; Linebergr, W.C., Determination of the singlet-triplet splitting and electron affinity of o-benzyne by negative ion photoelectron spectroscopy, J. Am. Chem. Soc., 1986, 108, 7, 1379, https://doi.org/10.1021/ja00267a003 . [all data]

Wenthold, Squires, et al., 1998, 2
Wenthold, P.G.; Squires, R.R.; Lineberger, W.C., Ultraviolet Photoelectron Spectroscopy of the, J. Am. Chem. Soc., 1998, 120, 21, 5279, https://doi.org/10.1021/ja9803355 . [all data]

Dunkin and MacDonald, 1979
Dunkin, I.R.; MacDonald, J.G., J. Chem. Soc., 1979, Chem. Commun. 772. [all data]

Chapman, Mattes, et al., 1973
Chapman, O.L.; Mattes, K.; McIntosh, C.L.; Pacansky, J.; Calder, G.V.; Orr, G., Photochemical transformations. LII. Benzyne, J. Am. Chem. Soc., 1973, 95, 18, 6134, https://doi.org/10.1021/ja00799a060 . [all data]

Nam and Leroi, 1987
Nam, H.-H.; Leroi, G.E., On the vibrational spectrum of matrix isolated o-benzyne, J. Mol. Struct., 1987, 157, 1-3, 301, https://doi.org/10.1016/0022-2860(87)87100-4 . [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]

Jacox, 2003
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement B, J. Phys. Chem. Ref. Data, 2003, 32, 1, 1-441, https://doi.org/10.1063/1.1497629 . [all data]

Brown, Godfrey, et al., 1986
Brown, R.D.; Godfrey, P.D.; Rodler, M., Microwave spectrum of benzyne, J. Am. Chem. Soc., 1986, 108, 6, 1296, https://doi.org/10.1021/ja00266a028 . [all data]

Robertson, Godfrey, et al., 2003
Robertson, E.G.; Godfrey, P.D.; McNaughton, D., The microwave spectrum of o-benzyne measured in a novel Stark modulated spectrometer for transient molecules, J. Mol. Spectrosc., 2003, 217, 1, 123, https://doi.org/10.1016/S0022-2852(02)00021-8 . [all data]

Kukolich, Tanjaroon, et al., 2003
Kukolich, S.G.; Tanjaroon, C.; McCarthy, M.C.; Thaddeus, P., Microwave spectrum of o-benzyne produced in a discharge nozzle, J. Chem. Phys., 2003, 119, 8, 4353, https://doi.org/10.1063/1.1593015 . [all data]

Kukolich, McCarthy, et al., 2004
Kukolich, S.G.; McCarthy, M.C.; Thaddeus, P., Molecular Structure of, J. Phys. Chem. A, 2004, 108, 14, 2645, https://doi.org/10.1021/jp031344p . [all data]

Notes

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  EA	Electron affinity
  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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