Benzyne
- Formula: C6H4
- Molecular weight: 76.0960
- IUPAC Standard InChIKey: KLYCPFXDDDMZNQ-UHFFFAOYSA-N
- CAS Registry Number: 462-80-6
- Chemical structure:
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Gas phase ion energetics data
Go To: Top, 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)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 201. | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 193.2 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
1.2650 ± 0.0080 | LPES | Wenthold, Squires, et al., 1998 | Triplet state 3.8±0.5 kcal/mol up.; B |
0.5640 ± 0.0070 | LPES | Wenthold, Squires, et al., 1998 | Triplet state 37.5±0.3 kcal/mol up.; B |
1.249 ± 0.022 | CIDT | Wenthold, Hu, et al., 1996 | B |
0.5594 ± 0.0087 | CIDT | Wenthold, Hu, et al., 1996 | B |
0.560 ± 0.010 | LPES | Leopold, Miller, et al., 1986 | B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.03 ± 0.05 | PE | Zhang and Chen, 1992 | LL |
9.24 | PE | Dewar and Tien, 1985 | LBLHLM |
8.95 | EST | Rosenstock, Stockbauer, et al., 1980 | LLK |
9.8 ± 0.2 | EI | Grutzmacher and Hubner, 1969 | RDSH |
9.5 ± 0.2 | EI | Grutzmacher and Lohmann, 1967 | RDSH |
De-protonation reactions
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 378.7 ± 3.1 | kcal/mol | G+TS | Guo and Grabowski, 1991 | gas phase; Acidity between MeOH and tBuOH, comparable to EtOH; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 371.0 ± 3.0 | kcal/mol | IMRB | Guo and Grabowski, 1991 | gas phase; Acidity between MeOH and tBuOH, comparable to EtOH; B |
ΔrG° | 372.0 ± 5.0 | kcal/mol | IMRB | Gronert and DePuy, 1989 | gas phase; B |
Vibrational and/or electronic energy levels
Go To: Top, 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: ?
Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
---|---|---|---|---|---|---|---|
Tx = 50200 | Ar | Munzel and Schweig, 1988 | |||||
Simon, Munzel, et al., 1990 | |||||||
State: ?
Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
---|---|---|---|---|---|---|---|
Tx = 40600 | Ar | Munzel and Schweig, 1988 | |||||
Simon, Munzel, et al., 1990 | |||||||
State: ?
Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
---|---|---|---|---|---|---|---|
Tx = 28730 | Ne | Radziszewski, Hess, et al., 1992 | |||||
State: ?
Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
---|---|---|---|---|---|---|---|
Tx = 26300 | Ar | Munzel and Schweig, 1988 | |||||
State: a
Energy (cm-1) |
Med. | Transition | λmin (nm) |
λmax (nm) |
References | ||
---|---|---|---|---|---|---|---|
To = 13140 ± 50 | gas | Leopold, Stevens-Miller, et al., 1986 | |||||
Wenthold, Squires, et al., 1998, 2 | |||||||
Vib. sym. |
No. | Approximate type of mode |
cm-1 | Med. | Method | References | |
---|---|---|---|---|---|---|---|
a1 | 1520 ± 40 | gas | PE | Wenthold, Squires, et al., 1998, 2 | |||
1395 ± 30 | gas | PE | Leopold, Stevens-Miller, et al., 1986 Wenthold, Squires, et al., 1998, 2 | ||||
1275 ± 30 | gas | PE | Wenthold, Squires, et al., 1998, 2 | ||||
560 ± 20 | gas | PE | Leopold, Stevens-Miller, et al., 1986 Wenthold, Squires, et al., 1998, 2 | ||||
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
w | Weak |
m | Medium |
s | Strong |
vs | Very strong |
o | Energy separation between the v = 0 levels of the excited and electronic ground states. |
x | Energy separation between the band maximum of the excited electronic state and the v = 0 level of the ground state. |
References
Go To: Top, 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.
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]
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]
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, 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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