Ethynyl radical

• Formula: C₂H
• Molecular weight: 25.0293
• IUPAC Standard InChI: InChI=1S/C2H/c1-2/h1H Copy

  
• IUPAC Standard InChIKey: XEHVFKKSDRMODV-UHFFFAOYSA-N Copy
• CAS Registry Number: 2122-48-7
• 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
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
• Data at other public NIST sites:
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Reaction thermochemistry 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 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

(C₂H₂^- • 4294967295) +  = C₂H₂^-

By formula: (C₂H₂^- • 4294967295C₂H) + C₂H = C₂H₂^-

Vibrational and/or electronic energy levels

Go To: Top, 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 compiled by: Marilyn E. Jacox

State:   3ps Ryd

State:   C

State:   B

State:   B'

State:   A

State:   X

Additional references: Jacox, 1994, page 32; Jacox, 1998, page 142; Jacox, 2003, page 28; Tucker, Kutner, et al., 1974; Okabe, 1975; Sastry, Helminger, et al., 1981; Ziurys, Saykally, et al., 1982; Gottlieb, Gottlieb, et al., 1983; Saito, Hikida, et al., 1984; Saykally, Veseth, et al., 1984; Suto and Lee, 1984; Fournier, Kaddouri, et al., 1985; Bogey, Demuynck, et al., 1985; Tiee, Sander, et al., 1985; Shokoohi, Watson, et al., 1986; Yan, Dane, et al., 1987; Vervloet and Herman, 1988; Kanamori and Hirota, 1988, 2; Brown and Evenson, 1988; Fletcher and Leone, 1989; Bogey, Demuynck, et al., 1989; Yan, Warner, et al., 1991; Schmidt, Peric, et al., 1998; Chiang and Hsu, 2000; Muller, Klaus, et al., 2000; Tarroni and Carter, 2003; Tarroni and Carter, 2004

Notes

References

Go To: Top, Reaction thermochemistry 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.

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]

Kiefer, Sidhu, et al., 1989
Kiefer, J.H.; Sidhu, S.S.; Kumaran, S.S.; Irdan, E.A., RRKM Model of C2H4 Dissociation: Heat of Formation of Vinylidene, Chem. Phys. Lett., 1989, 159, 1, 32, https://doi.org/10.1016/S0009-2614(89)87448-2 . [all data]

Guo and Grabowski, 1990
Guo, Y.; Grabowski, J.J., Gas Phase Ion Chemistry of the Vinylidene Radical Anion and the Acidity of the Vinyl Radical, Int. J. Mass Spectrom. Ion Proc., 1990, 97, 3, 253, https://doi.org/10.1016/0168-1176(90)85003-K . [all data]

Cool and Goodwin, 1991
Cool, T.A.; Goodwin, P.M., Observation of an electronic state of C2H near 9 eV by resonance ionization spectroscopy, J. Chem. Phys., 1991, 94, 11, 6978, https://doi.org/10.1063/1.460231 . [all data]

Chang and Graham, 1982
Chang, K.W.; Graham, W.R.M., Vacuum UV spectra of photolyzed C2H2 in solid Ar at 8 K, J. Chem. Phys., 1982, 76, 11, 5238, https://doi.org/10.1063/1.442919 . [all data]

Hsu, Wang, et al., 1992
Hsu, Y.-C.; Wang, P.-R.; Yang, M.-C.; Papousek, D.; Chen, Y.-T.; Chiang, W.-Y., Ultraviolet laser-induced fluorescence of the C2H radical, Chem. Phys. Lett., 1992, 190, 5, 507, https://doi.org/10.1016/0009-2614(92)85182-A . [all data]

Hsu, Lin, et al., 1993
Hsu, Y.-C.; Lin, J.J.-M.; Papousek, D.; Tsai, J.-J., The low-lying bending vibrational levels of the CCH (X 2Σ+) radical studied by laser-induced fluorescence, J. Chem. Phys., 1993, 98, 9, 6690, https://doi.org/10.1063/1.464761 . [all data]

Some, Remy, et al., 1995
Some, E.; Remy, F.; Macau-Hercot, D.; Dubois, I.; Breton, J.; Bredohl, H., The Near UV Emission Spectrum of C2H, J. Mol. Spectrosc., 1995, 173, 1, 44, https://doi.org/10.1006/jmsp.1995.1216 . [all data]

Hsu, Shiu, et al., 1995
Hsu, Y.-C.; Shiu, Y.-J.; Lin, C.-M., Laser-induced fluorescence spectroscopy of CCH (X 2Σ+) in vibrationally excited levels up to 4500 cm-1, J. Chem. Phys., 1995, 103, 14, 5919, https://doi.org/10.1063/1.470472 . [all data]

Chiang and Hsu, 1999
Chiang, W.-Y.; Hsu, Y.-C., Laser spectroscopy of CCH in the 36 600--39 700 cm[sup -1] region, J. Chem. Phys., 1999, 111, 4, 1454, https://doi.org/10.1063/1.479389 . [all data]

Fahr, 2003
Fahr, A., Ultraviolet absorption spectrum and cross-sections of ethynyl (C2H) radicals, J. Mol. Spectrosc., 2003, 217, 2, 249, https://doi.org/10.1016/S0022-2852(02)00039-5 . [all data]

Graham, Dismuke, et al., 1974
Graham, W.R.M.; Dismuke, K.I.; Weltner, W., Jr., C2H radical: 13C hyperfine interaction and optical spectrum, J. Chem. Phys., 1974, 60, 10, 3817, https://doi.org/10.1063/1.1680824 . [all data]

Carrick, Merer, et al., 1983
Carrick, P.G.; Merer, A.J.; Curl, R.F., A 2Π←X 2Σ+ infrared electronic transition of C2Ha), J. Chem. Phys., 1983, 78, 6, 3652, https://doi.org/10.1063/1.445112 . [all data]

Curl, Carrick, et al., 1985
Curl, R.F.; Carrick, P.G.; Merer, A.J., Rotational analysis of the A ← X system of C2Ha), J. Chem. Phys., 1985, 82, 8, 3479, https://doi.org/10.1063/1.448927 . [all data]

Yan, Hall, et al., 1987
Yan, W.-B.; Hall, J.L.; Stephens, J.W.; Richnow, M.L.; Curl, R.F., Color center laser spectroscopy of vibrationally excited C2H, J. Chem. Phys., 1987, 86, 4, 1657, https://doi.org/10.1063/1.452163 . [all data]

Kanamori and Hirota, 1988
Kanamori, H.; Hirota, E., Vibronic bands of the CCH radical observed by infrared diode laser kinetic spectroscopy, J. Chem. Phys., 1988, 89, 7, 3962, https://doi.org/10.1063/1.454877 . [all data]

Kawaguchi, Amano, et al., 1988
Kawaguchi, K.; Amano, T.; Hirota, E., Infrared diode laser spectroscopy of the ν2 + ν3 band of CCH, J. Mol. Spectrosc., 1988, 131, 1, 58, https://doi.org/10.1016/0022-2852(88)90106-3 . [all data]

Ervin and Lineberger, 1991
Ervin, K.M.; Lineberger, W.C., Photoelectron Spectra of C2- and C2H-, J. Phys. Chem., 1991, 95, 3, 1167, https://doi.org/10.1021/j100156a026 . [all data]

Yan and Amano, 1993
Yan, W.-B.; Amano, T., Difference-frequency laser spectroscopy of the 3ν2+ν3 band of C2H, J. Chem. Phys., 1993, 99, 6, 4312, https://doi.org/10.1063/1.466084 . [all data]

Pfelzer, Havenith, et al., 1996
Pfelzer, C.; Havenith, M.; Peric, M.; Murtz, P.; Urban, W., Faraday Laser Magnetic Resonance Spectroscopy of Vibrationally Excited C2H, J. Mol. Spectrosc., 1996, 176, 1, 28, https://doi.org/10.1006/jmsp.1996.0058 . [all data]

Hsu, Chen, et al., 1996
Hsu, Y.-C.; Chen, F.-T.; Chou, L.-C.; Shiu, Y.-J., 193.3 nm photodissociation of acetylene: Nascent state distribution of CCH radical studied by laser-induced fluorescence, J. Chem. Phys., 1996, 105, 20, 9153, https://doi.org/10.1063/1.472763 . [all data]

Taylor, Xu, et al., 1998
Taylor, T.R.; Xu, C.; Neumark, D.M., Photoelectron spectra of the C[sub 2n]H[sup -] (n=1--4) and C[sub 2n]D[sup -] (n=1--3) anions, J. Chem. Phys., 1998, 108, 24, 10018, https://doi.org/10.1063/1.476462 . [all data]

Boye, Campos, et al., 2002
Boye, S.; Campos, A.; Douin, S.; Fellows, C.; Gauyacq, D.; Shafizadeh, N.; Halvick, Ph.; Boggio-Pasqua, M., Visible emission from the vibrationally hot C[sub 2]H radical following vacuum-ultraviolet photolysis of acetylene: Experiment and theory, J. Chem. Phys., 2002, 116, 20, 8843, https://doi.org/10.1063/1.1471239 . [all data]

Sharp-Williams, Roberts, et al., 2011
Sharp-Williams, E.N.; Roberts, M.A.; Nesbitt, D.J., High resolution slit-jet infrared spectroscopy of ethynyl radical: 2Π--2Σ+ vibronic bands with sub-Doppler resolution, J. Chem. Phys., 2011, 134, 6, 064314, https://doi.org/10.1063/1.3532088 . [all data]

Forney, Jacox, et al., 1995
Forney, D.; Jacox, M.E.; Thompson, W.E., The Infrared and Near-Infrared Spectra of HCC and DCC Trapped in Solid Neon, J. Mol. Spectrosc., 1995, 170, 1, 178, https://doi.org/10.1006/jmsp.1995.1065 . [all data]

Jacox and Olson, 1987
Jacox, M.E.; Olson, W.B., The A 2Π--X 2Σ+ transition of HC2 isolated in solid argon, J. Chem. Phys., 1987, 86, 6, 3134, https://doi.org/10.1063/1.452024 . [all data]

Stephens, Yan, et al., 1988
Stephens, J.W.; Yan, W.-B.; Richnow, M.L.; Solka, H.; Curl, R.F., Infrared kinetic spectroscopy of C2H and C2D, J. Mol. Struct., 1988, 190, 41, https://doi.org/10.1016/0022-2860(88)80269-2 . [all data]

Wu and Cheng, 2008
Wu, Y.-J.; Cheng, B.-M., Infrared absorption spectra of ethynyl radicals isolated in solid Ne: Identification of the fundamental C--H stretching mode, Chem. Phys. Lett., 2008, 461, 1-3, 53, https://doi.org/10.1016/j.cplett.2008.07.008 . [all data]

Zhou, Garand, et al., 2007
Zhou, J.; Garand, E.; Neumark, D.M., Vibronic structure in C2H and C2D from anion slow electron velocity-map imaging spectroscopy, J. Chem. Phys., 2007, 127, 11, 114313, https://doi.org/10.1063/1.2768932 . [all data]

Kanamori, Seki, et al., 1987
Kanamori, H.; Seki, K.; Hirota, E., Infrared diode laser kinetic spectroscopy of the CCH radical ν3 band, J. Chem. Phys., 1987, 87, 1, 73, https://doi.org/10.1063/1.453571 . [all data]

Andrews, Kushto, et al., 1999
Andrews, L.; Kushto, G.P.; Zhou, M.; Willson, S.P.; Souter, P.F., Infrared spectrum of CCH[sup +] in solid argon and neon, J. Chem. Phys., 1999, 110, 9, 4457, https://doi.org/10.1063/1.478329 . [all data]

Milligan, Jacox, et al., 1967
Milligan, D.E.; Jacox, M.E.; Abouaf-Marguin, L., Vacuum-Ultraviolet Photolysis of Acetylene in Inert Matrices. Spectroscopic Study of the Species C2, J. Chem. Phys., 1967, 46, 12, 4562, https://doi.org/10.1063/1.1840602 . [all data]

Jacox, 1975
Jacox, M.E., Matrix isolation study of the vibrational spectrum and structure of HC2, Chem. Phys., 1975, 7, 3, 424, https://doi.org/10.1016/0301-0104(75)87025-X . [all data]

Shepherd and Graham, 1987
Shepherd, R.A.; Graham, W.R.M., FTIR study of D and 13C substituted C2H in solid argon, J. Chem. Phys., 1987, 86, 5, 2600, https://doi.org/10.1063/1.452062 . [all data]

Tanskanen, Khriachtchev, et al., 2004
Tanskanen, H.; Khriachtchev, L.; Lundell, J.; Rasanen, M., Organo-noble-gas hydride compounds HKrCCH, HXeCCH, HXeCC, and HXeCCXeH: Formation mechanisms and effect of [sup 13]C isotope substitution on the vibrational properties, J. Chem. Phys., 2004, 121, 17, 8291, https://doi.org/10.1063/1.1799611 . [all data]

Khriachtchev, Tanskanen, et al., 2003
Khriachtchev, L.; Tanskanen, H.; Lundell, J.; Pettersson, M.; Kiljunen, H.; Rasanen, M., Fluorine-Free Organoxenon Chemistry: HXeCCH, HXeCC, and HXeCCXeH, J. Am. Chem. Soc., 2003, 125, 16, 4696, https://doi.org/10.1021/ja034485d . [all data]

Feldman, Sukhov, et al., 2003
Feldman, V.I.; Sukhov, F.F.; Orlov, A.Yu.; Tyulpina, I.V., Experimental Evidence for the Formation of HXeCCH: The First Hydrocarbon with an Inserted Rare-Gas Atom, J. Am. Chem. Soc., 2003, 125, 16, 4698, https://doi.org/10.1021/ja034585j . [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, 1998
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement A, J. Phys. Chem. Ref. Data, 1998, 27, 2, 115-393, https://doi.org/10.1063/1.556017 . [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]

Tucker, Kutner, et al., 1974
Tucker, K.D.; Kutner, M.L.; Thaddeus, P., The ethynyl radical C2H - A new interstellar molecule, Astrophys. J., 1974, 193, L115, https://doi.org/10.1086/181646 . [all data]

Okabe, 1975
Okabe, H., J. Chem. Phys., 1975, 62, 2782. [all data]

Sastry, Helminger, et al., 1981
Sastry, K.V.L.N.; Helminger, P.; Charo, A.; Herbst, E.; De Lucia, F.C., Laboratory millimeter and submillimeter spectrum of CCH, Astrophys. J., 1981, 251, L119, https://doi.org/10.1086/183706 . [all data]

Ziurys, Saykally, et al., 1982
Ziurys, L.M.; Saykally, R.J.; Plambeck, R.L.; Erickson, N.R., Detection of the N = 3-2 transition of CCH in Orion and determination of the molecular rotational constants, Astrophys. J., 1982, 254, 94, https://doi.org/10.1086/159709 . [all data]

Gottlieb, Gottlieb, et al., 1983
Gottlieb, C.A.; Gottlieb, E.W.; Thaddeus, P., Laboratory and astronomical measurement of the millimeter wave spectrum of the ethynyl radical CCH, Astrophys. J., 1983, 264, 740, https://doi.org/10.1086/160647 . [all data]

Saito, Hikida, et al., 1984
Saito, Y.; Hikida, T.; Ichimura, T.; Mori, Y., Fluorescence of excited ethynyl radicals produced by pulsed vacuum ultraviolet photolyses of C2H2, C2D2, and C2HBr, J. Chem. Phys., 1984, 80, 1, 31, https://doi.org/10.1063/1.446448 . [all data]

Saykally, Veseth, et al., 1984
Saykally, R.J.; Veseth, L.; Evenson, K.M., Laser magnetic resonance rotational spectroscopy of 2Σ radicals: Ethynyl (CCH), J. Chem. Phys., 1984, 80, 6, 2247, https://doi.org/10.1063/1.447001 . [all data]

Suto and Lee, 1984
Suto, M.; Lee, L.C., Quantitative photoexcitation and fluorescence studies of C2H2 in vacuum ultraviolet, J. Chem. Phys., 1984, 80, 10, 4824, https://doi.org/10.1063/1.446503 . [all data]

Fournier, Kaddouri, et al., 1985
Fournier, J.; Kaddouri, A.; Berthier, G., Evidence of emission from an excited linear triplet state in the photolysis of acetylene trapped in a rigid matrix at 4.8 K, J. Phys. Chem., 1985, 89, 19, 4120, https://doi.org/10.1021/j100265a038 . [all data]

Bogey, Demuynck, et al., 1985
Bogey, M.; Demuynck, C.; Destombes, J.L., Astron. Astrophys., 1985, 144, L15. [all data]

Tiee, Sander, et al., 1985
Tiee, J.J.; Sander, R.K.; Quick, C.R., Jr.; Romero, R.J.; Estler, R., Proc. SPIE 540 (Proc. Southwest Conf. Optics), 1985, 322. [all data]

Shokoohi, Watson, et al., 1986
Shokoohi, F.; Watson, T.A.; Reisler, H.; Kong, F.; Renlund, A.M.; Wittig, C., Photolytic production of ethynyl radical (C2H): collisional quenching of A2.PI. .fwdarw. X2.SIGMA.+ infrared emission and the removal of excited C2H, J. Phys. Chem., 1986, 90, 22, 5695, https://doi.org/10.1021/j100280a044 . [all data]

Yan, Dane, et al., 1987
Yan, W.-B.; Dane, C.B.; Zeitz, D.; Hall, J.; Curl, R.F., Color center laser spectroscopy of C2H and C2D, J. Mol. Spectrosc., 1987, 123, 2, 486, https://doi.org/10.1016/0022-2852(87)90294-3 . [all data]

Vervloet and Herman, 1988
Vervloet, M.; Herman, M., Fourier transform emission spectroscopy of C2H, Chem. Phys. Lett., 1988, 144, 1, 48, https://doi.org/10.1016/0009-2614(88)87087-8 . [all data]

Kanamori and Hirota, 1988, 2
Kanamori, H.; Hirota, E., Infrared diode laser kinetic spectroscopy of the CCD radical ν3 band, J. Chem. Phys., 1988, 88, 11, 6699, https://doi.org/10.1063/1.454414 . [all data]

Brown and Evenson, 1988
Brown, J.M.; Evenson, K.M., The far-infrared laser magnetic resonance spectrum of vibrationally excited C2H, J. Mol. Spectrosc., 1988, 131, 1, 161, https://doi.org/10.1016/0022-2852(88)90115-4 . [all data]

Fletcher and Leone, 1989
Fletcher, T.R.; Leone, S.R., Photodissociation dynamics of C2H2 at 193 nm: Vibrational distributions of the CCH radical and the rotational state distribution of the A(010) state by time-resolved Fourier transform infrared emission, J. Chem. Phys., 1989, 90, 2, 871, https://doi.org/10.1063/1.456112 . [all data]

Bogey, Demuynck, et al., 1989
Bogey, M.; Demuynck, C.; Destombes, J.L., Submillimetre wave spectra of the, Mol. Phys., 1989, 66, 5, 955, https://doi.org/10.1080/00268978900100651 . [all data]

Yan, Warner, et al., 1991
Yan, W.-B.; Warner, H.E.; Amano, T., Difference-frequency laser spectroscopy of gas phase C2D in the 2800 cm-1 region, J. Chem. Phys., 1991, 94, 3, 1712, https://doi.org/10.1063/1.459943 . [all data]

Schmidt, Peric, et al., 1998
Schmidt, C.; Peric, M.; Murtz, P.; Wienkoop, M.; Havenith, M.; Urban, W., Faraday Laser Magnetic Resonance Spectroscopy of Vibrationally Excited C2D, J. Mol. Spectrosc., 1998, 190, 1, 112, https://doi.org/10.1006/jmsp.1998.7563 . [all data]

Chiang and Hsu, 2000
Chiang, W.-Y.; Hsu, Y.-C., Fluorescence lifetimes and predissociation processes in the B [sup 2]A[sup ´] state of CCH, J. Chem. Phys., 2000, 112, 17, 7394, https://doi.org/10.1063/1.481339 . [all data]

Muller, Klaus, et al., 2000
Muller, H.S.P.; Klaus, T.; Winnewisser, G., Astron. Astrophys., 2000, 357, L65. [all data]

Tarroni and Carter, 2003
Tarroni, R.; Carter, S., Theoretical calculation of vibronic levels of C[sub 2]H and C[sub 2]D to 10 000 cm[sup -1], J. Chem. Phys., 2003, 119, 24, 12878, https://doi.org/10.1063/1.1627755 . [all data]

Tarroni and Carter, 2004
Tarroni, R.; Carter, S., Theoretical calculation of absorption intensities of C, Mol. Phys., 2004, 102, 21-22, 2167, https://doi.org/10.1080/00268970410001713254 . [all data]

Notes

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

• Symbols used in this document:
  

  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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