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.
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Vibrational and/or electronic energy levels
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
• Options:
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Gas phase thermochemistry data

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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Reaction 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.

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, Gas phase thermochemistry data, Reaction thermochemistry data, 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

References

Go To: Top, Gas phase thermochemistry data, Reaction 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.

Riveros, Ingeman, et al., 1991
Riveros, J.M.; Ingeman, S.; Nibbering, N.M.M., Formation of gas-phase solvated Br-and I- ion/molecule reactions of halobenzenes. Revised heat of formation of benzyne, J. Am. Chem. Soc., 1991, 113, 1053. [all data]

Wenthold, Paulino, et al., 1991
Wenthold, P.G.; Paulino, J.A.; Squires, R.R., The absolute heats of formation of o-,m-, and p-benzyne, J. Am. Chem. Soc., 1991, 113, 7414-7415. [all data]

Pollack and Hehre, 1980
Pollack, S.K.; Hehre, W.J., Determination of the heat of formation of ortho-benzyne by ion cyclotron resonance spectroscopy, Tetrahedron Lett., 1980, 21, 2483-2486. [all data]

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, 2
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]

Notes

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

• Symbols used in this document:
  

  EA	Electron affinity
  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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