Vinyl radical

Formula: C₂H₃
Molecular weight: 27.0452
IUPAC Standard InChI: InChI=1S/C2H3/c1-2/h1H,2H2
IUPAC Standard InChIKey: ORGHESHFQPYLAO-UHFFFAOYSA-N
CAS Registry Number: 2669-89-8
Chemical structure:
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Gas phase ion energetics data

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Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
B - John E. Bartmess

View reactions leading to C₂H₃⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	180.5	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	172.0	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_{(+) ion}	262. ± 3.	kcal/mol	N/A	N/A
Quantity	Value	Units	Method	Reference	Comment
Δ_fH_{(+) ion,0K}	263. ± 3.	kcal/mol	N/A	N/A

Electron affinity determinations

EA (eV)	Method	Reference	Comment
0.667 ± 0.024	LPES	Ervin, Gronert, et al., 1990	B
>0.39999	IMRB	Lindinger, Albritton, et al., 1975	B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
8.25	PE	Blush and Chen, 1992	LL
≤8.59 ± 0.03	PI	Berkowitz, Mayhew, et al., 1988	LL
8.7 ± 0.1	DER	Reinke, Kraessig, et al., 1973	LLK
8.95	EI	Lossing, 1971	LLK

References

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

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]

Ervin, Gronert, et al., 1990
Ervin, K.M.; Gronert, S.; Barlow, S.E.; Gilles, M.K.; Harrison, A.G.; Bierbaum, V.M.; DePuy, C.H.; Lin, W.C., Bonds Strengths of Ethylene and Acetylene, J. Am. Chem. Soc., 1990, 112, 15, 5750, https://doi.org/10.1021/ja00171a013 . [all data]

Lindinger, Albritton, et al., 1975
Lindinger, W.; Albritton, A.L.; Fehsenfeld, F.C.; Ferguson, E.E., Reactions of O- with N₂, N₂O, SO₂, NH₃, CH₄, C₂H₄, and C₂H₂- with O₂ from 300K to relative kinetic energies of 2 eV, J. Chem. Phys., 1975, 63, 3238. [all data]

Blush and Chen, 1992
Blush, J.A.; Chen, P., Photoelectron spectrum of the vinyl radical. Downward revision of C₂H₃ ionization potential, J. Phys. Chem., 1992, 96, 4138. [all data]

Berkowitz, Mayhew, et al., 1988
Berkowitz, J.; Mayhew, C.A.; Ruscic, B., A photoionization study of the vinyl radical, J. Chem. Phys., 1988, 88, 7396. [all data]

Reinke, Kraessig, et al., 1973
Reinke, D.; Kraessig, R.; Baumgartel, H., Photoreactions of small organic molecules, Z. Naturforsch. A:, 1973, 28, 1021. [all data]

Lossing, 1971
Lossing, F.P., Free radicals by mass spectrometry. XLIII. Ionization potentials and ionic heats of formation for vinyl, allyl, and benzyl radicals, Can. J. Chem., 1971, 49, 357. [all data]

Notes

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Symbols used in this document:

EA Electron affinity

Δ_fH_{(+) ion,0K} Enthalpy of formation of positive ion at 0K
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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EA	Electron affinity
Δ_fH_{(+) ion,0K}	Enthalpy of formation of positive ion at 0K