Home Symbol which looks like a small house Up Solid circle with an upward pointer in it

NOTICE: Due to scheduled maintenance at our Gaithersburg campus, this site will not be available from 5:00 pm EDT (21:00 UTC) on Friday October 25 until 5:00 pm (21:00 UTC) on Sunday October 27. We apologize for any inconvenience this outage may cause.

Isocyanato radical


Gas phase ion energetics data

Go To: Top, Vibrational and/or electronic energy levels, NIST Free Links, 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:
L - Sharon G. Lias

Data compiled as indicated in comments:
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
B - John E. Bartmess

View reactions leading to CNO+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)11.76 ± 0.01eVN/AN/AL

Electron affinity determinations

EA (eV) Method Reference Comment
3.6090 ± 0.0050LPESBradforth, Kim, et al., 1993D-EA cycle requires a DH ca 4 kcal/mol weaker; B
3.454 ± 0.095D-EAWight and Beauchamp, 1980B
3.80 ± 0.20EIAEOster and Illenberger, 1988B
>2.60 ± 0.40EIAEThynne, 1972From PF2NCO; B

Ionization energy determinations

IE (eV) Method Reference Comment
11.759 ± 0.006PIRuscic and Berkowitz, 1994LL
11.76 ± 0.01PEDyke, Jonathan, et al., 1983LBLHLM

Vibrational and/or electronic energy levels

Go To: Top, Gas phase ion energetics data, NIST Free Links, 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:   B


 Energy 
 (cm-1
 Med.   Transition   «lambda»min 
 (nm) 
 «lambda»max 
 (nm) 
 References

To = 31744.81 gas B-X 265 320 Dixon, 1960
Dixon, Trenouth, et al., 1987
Cyr, Continetti, et al., 1992
Wright and Dagdigian, 1996
Yao, Fernandez, et al., 1997
Elliott, Fitzpatrick, et al., 2008
To = 31616 ± 25 Ne B-X 260 320 Milligan and Jacox, 1967
To = 31437 ± 25 Ar B-X 232 315 Milligan and Jacox, 1967
To = 31339 ± 25 N2 B-X 256 315 Milligan and Jacox, 1967


Vib. 
sym. 
 No.   Approximate 
 type of mode 
 cm-1   Med.   Method   References

Sigma+ 1 Stretch 2303 gas UV Dixon, 1960
1 Stretch 2295 ± 50 Ne UV Milligan and Jacox, 1967
1 Stretch 2303 ± 50 Ar UV Milligan and Jacox, 1967
3 Stretch 1047 gas UV Dixon, 1960
3 Stretch 1033 ± 50 Ne UV Milligan and Jacox, 1967
3 Stretch 1053 ± 50 Ar UV Milligan and Jacox, 1967
3 Stretch 1025 ± 50 N2 UV Milligan and Jacox, 1967

State:   A


 Energy 
 (cm-1
 Med.   Transition   «lambda»min 
 (nm) 
 «lambda»max 
 (nm) 
 References

To = 22754.020 ± 0.002 gas A-X 304 512 Dixon, 1960, 2
Patel-Misra, Sauder, et al., 1990
Wu, Northrup, et al., 1992
Hemmerling and Vervloet, 1993
Wright and Dagdigian, 1996
Yao, Fernandez, et al., 1997
Elliott, Fitzpatrick, et al., 2008
To = 22800 ± 10 Ne A-X 398 440 Milligan and Jacox, 1967
To = 22712 ± 2 Ar A-X 390 530 Bondybey and English, 1977
To = 22956 ± 10 N2 A-X 395 440 Milligan and Jacox, 1967


Vib. 
sym. 
 No.   Approximate 
 type of mode 
 cm-1   Med.   Method   References

Sigma+ 1 Stretch 2337.7 gas UV LF Dixon, 1960, 2
Elliott, Fitzpatrick, et al., 2008
1 Stretch 2325 ± 20 Ne UV Milligan and Jacox, 1967
1 Stretch 2332 ± 4 Ar UV LF Milligan and Jacox, 1967
Bondybey and English, 1977
1 Stretch 2321 ± 20 N2 UV Milligan and Jacox, 1967
Pi 2 Bend 680.4 gas UV LF Dixon, 1960, 2
Elliott, Fitzpatrick, et al., 2008
2 Bend 673 ± 20 Ne UV Milligan and Jacox, 1967
Sigma+ 3 Stretch 1289.3 gas UV LF Dixon, 1960, 2
Elliott, Fitzpatrick, et al., 2008
3 Stretch 1270 ± 20 Ne UV Milligan and Jacox, 1967
3 Stretch 1291 ± 4 Ar UV LF Milligan and Jacox, 1967
Bondybey and English, 1977

State:   X


Vib. 
sym. 
 No.   Approximate 
 type of mode 
 cm-1   Med.   Method   References

Sigma+ 1 Sym.stretch 1266.63 ± 0.08 gas LF LMR Wong, Anderson, et al., 1984
Copeland, 1984
Werner, Seebass, et al., 1985
Woodward, Fletcher, et al., 1987
Patel-Misra, Sauder, et al., 1990
1 Sym.stretch 1266.63 ± 0.08 gas SEP Wu, Northrup, et al., 1992
Wu and Sears, 1994
1 Sym.stretch 1275 w Ar IR LF Milligan and Jacox, 1967
Bondybey and English, 1977
1 Sym.stretch 1269.0 Xe IR Pettersson, Khriachtchev, et al., 1999
Pi 2 Bend (w) 535.43 gas UV LF Dixon, 1960, 2
Bolman, Brown, et al., 1975
Copeland, 1984
2 Bend (w) 535.43 gas SEP LMR Patel-Misra, Sauder, et al., 1990
Wu and Sears, 1994
Gillett, Cooksy, et al., 2006
2 Bend («kappa» 2S-) 669.28 gas UV LF Bolman, Brown, et al., 1975
Copeland, 1984
Patel-Misra, Sauder, et al., 1990
2 Bend («kappa» 2S-) 672 Ar LF Bondybey and English, 1977
2 Bend (2D3/2) 628.45 gas UV LF Bolman, Brown, et al., 1975
Copeland, 1984
Patel-Misra, Sauder, et al., 1990
2 Bend (2D3/2) 626 Ar LF Bondybey and English, 1977
2 Bend (2D5/2) 534.64 gas UV LF Bolman, Brown, et al., 1975
Copeland, 1984
Patel-Misra, Sauder, et al., 1990
2 Bend (2D5/2) 529.5 Ar LF Bondybey and English, 1977
2 Bend («mu» 2S+) 488.43 gas UV LF Bolman, Brown, et al., 1975
Copeland, 1984
Patel-Misra, Sauder, et al., 1990
2 Bend («mu» 2S+) 487 Ar IR LF Milligan and Jacox, 1967
Bondybey and English, 1977
Sigma+ 3 Asym. stretch 1921.28 gas LMR LF Barnes, Brown, et al., 1982
Wong, Anderson, et al., 1984
Copeland, 1984
Patel-Misra, Sauder, et al., 1990
3 Asym. stretch 1921.28 gas DL EM Bruggemann, Petri, et al., 1989
Hemmerling and Vervloet, 1993
Gillett, Cooksy, et al., 2006
3 Asym. stretch 1921.28 gas SEP Northrup, Wu, et al., 1992
3 Asym. stretch 1923 m Ar IR LF Milligan and Jacox, 1967
Bondybey and English, 1977
3 Asym. stretch 1921.6 Kr IR Pettersson, Khriachtchev, et al., 1999
3 Asym. stretch 1917.8 Xe IR Pettersson, Khriachtchev, et al., 1999
3 Asym. stretch 1915.8 Xe IR Pettersson, Khriachtchev, et al., 1999
3 Asym. stretch 1935 N2 IR Milligan and Jacox, 1967

Additional references: Jacox, 1994, page 76; Jacox, 1998, page 184; Jacox, 2003, page 122; Carrington, Fabris, et al., 1968; Saito and Amano, 1970; Amano and Hirota, 1972; Reisler, Mangir, et al., 1980; Hancock and Ketley, 1982; Charlton, Okamura, et al., 1982; Sullivan, Smith, et al., 1983; Kawaguchi, Saito, et al., 1985; Misra, Mathews, et al., 1988; Davies and Davis, 1990; Patel-Misra, Sauder, et al., 1991; Hoops, Bise, et al., 2001

Notes

wWeak
mMedium
oEnergy separation between the v = 0 levels of the excited and electronic ground states.

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, NIST Free Links, Notes

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

Bradforth, Kim, et al., 1993
Bradforth, S.E.; Kim, E.H.; Arnold, D.W.; Neumark, D.M., Photoelectron Spectroscopy of CN-, NCO-, and NCS-, J. Chem. Phys., 1993, 98, 2, 800, https://doi.org/10.1063/1.464244 . [all data]

Wight and Beauchamp, 1980
Wight, C.A.; Beauchamp, J.L., Acidity, basicity, and ion/molecule reactions of isocyanic acid in the gas phase by ICR spectroscopy, J. Phys. Chem., 1980, 84, 2503. [all data]

Oster and Illenberger, 1988
Oster, T.; Illenberger, E., Negative Ion Formation in SF5NCO Following Low Energy Electron Attachment, Int. J. Mass Spectrom. Ion Proc., 1988, 85, 1, 125, https://doi.org/10.1016/0168-1176(88)83010-6 . [all data]

Thynne, 1972
Thynne, J.C.J., Negative Ion Studies with a Time-of-Flight Mass Spectrometer., Dyn. Mass Spectrom., 1972, 3, 67. [all data]

Ruscic and Berkowitz, 1994
Ruscic, B.; Berkowitz, J., The H-NCO bond energy and Hf(NCO) from photoionization mass spectrometric studies of HNCO and NCO, J. Chem. Phys., 1994, 100, 4498. [all data]

Dyke, Jonathan, et al., 1983
Dyke, J.M.; Jonathan, N.; Lewis, A.E.; Mills, J.D.; Morris, A., Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 16. The NCO (X2«PI») radical, Mol. Phys., 1983, 50, 77. [all data]

Dixon, 1960
Dixon, R.N., A, Can. J. Phys., 1960, 38, 1, 10, https://doi.org/10.1139/p60-002 . [all data]

Dixon, Trenouth, et al., 1987
Dixon, R.N.; Trenouth, M.J.; Western, C.M., An optical-optical double resonance study of the, Mol. Phys., 1987, 60, 4, 779, https://doi.org/10.1080/00268978700100541 . [all data]

Cyr, Continetti, et al., 1992
Cyr, D.R.; Continetti, R.E.; Metz, R.B.; Osborn, D.L.; Neumark, D.M., Fast beam studies of NCO free radical photodissociation, J. Chem. Phys., 1992, 97, 7, 4937, https://doi.org/10.1063/1.463989 . [all data]

Wright and Dagdigian, 1996
Wright, S.A.; Dagdigian, P.J., Radiative and nonradiative decay of electronically excited NCO, J. Chem. Phys., 1996, 104, 21, 8279, https://doi.org/10.1063/1.471580 . [all data]

Yao, Fernandez, et al., 1997
Yao, J.; Fernandez, J.A.; Bernstein, E.R., On the A and B electronic states of NCO and its clusters with nonpolar solvents, J. Chem. Phys., 1997, 107, 21, 8813, https://doi.org/10.1063/1.475173 . [all data]

Elliott, Fitzpatrick, et al., 2008
Elliott, N.L.; Fitzpatrick, J.A.J.; Western, C.M., Sub-Doppler spectroscopy of the A [sup 2]«SIGMA»[sup +]-X [sup 2]«PI» and B [sup 2]«PI»-X [sup 2]«PI» transitions of NCO, J. Chem. Phys., 2008, 129, 16, 164301, https://doi.org/10.1063/1.2987305 . [all data]

Milligan and Jacox, 1967
Milligan, D.E.; Jacox, M.E., Matrix-Isolation Study of the Infrared and Ultraviolet Spectra of the Free Radical NCO, J. Chem. Phys., 1967, 47, 12, 5157, https://doi.org/10.1063/1.1701773 . [all data]

Dixon, 1960, 2
Dixon, R.N., The Absorption Spectrum of the Free NCO Radical, Phil. Trans. Roy. Soc. (London) A252, 1960, 252, 1007, 165, https://doi.org/10.1098/rsta.1960.0003 . [all data]

Patel-Misra, Sauder, et al., 1990
Patel-Misra, D.; Sauder, D.G.; Dagdigian, P.J., Observation of highly excited bending levels in NCO(X 2«PI»), J. Chem. Phys., 1990, 93, 8, 5448, https://doi.org/10.1063/1.459641 . [all data]

Wu, Northrup, et al., 1992
Wu, M.; Northrup, F.J.; Sears, T.J., Study of Renner--Teller, spin--orbit, and Fermi-resonance interactions in X 2«PI» (v1v20) levels of NCO by stimulated emission pumping spectroscopy, J. Chem. Phys., 1992, 97, 7, 4583, https://doi.org/10.1063/1.463861 . [all data]

Hemmerling and Vervloet, 1993
Hemmerling, B.; Vervloet, M., Analysis of the electronic emission Ã, Mol. Phys., 1993, 78, 6, 1423, https://doi.org/10.1080/00268979300100941 . [all data]

Bondybey and English, 1977
Bondybey, V.E.; English, J.H., Fermi resonance and vibrational relaxation in the A 2«SIGMA» state of NCO in solid argon, J. Chem. Phys., 1977, 67, 6, 2868, https://doi.org/10.1063/1.435154 . [all data]

Wong, Anderson, et al., 1984
Wong, K.N.; Anderson, W.R.; Kotlar, A.J.; Vanderhoff, J.A., Investigation of several low-lying levels of X 2«PI» NCO using argon laser excited fluorescence, J. Chem. Phys., 1984, 81, 7, 2970, https://doi.org/10.1063/1.448047 . [all data]

Copeland, 1984
Copeland, R.A., and D. R. Crosley, 1984, Can. J. Phys. 62, 1488. [all data]

Werner, Seebass, et al., 1985
Werner, J.; Seebass, W.; Koch, M.; Curl, R.F.; Urban, W.; Brown, J.M., An observation of the, Mol. Phys., 1985, 56, 2, 453, https://doi.org/10.1080/00268978500102441 . [all data]

Woodward, Fletcher, et al., 1987
Woodward, D.R.; Fletcher, D.A.; Brown, J.M., Dispersed fluorescence studies of the NCO radical, Mol. Phys., 1987, 62, 2, 517, https://doi.org/10.1080/00268978700102381 . [all data]

Wu and Sears, 1994
Wu, M.; Sears, T.J., Stimulated emission pumping spectroscopy of, Mol. Phys., 1994, 82, 3, 503, https://doi.org/10.1080/00268979400100374 . [all data]

Pettersson, Khriachtchev, et al., 1999
Pettersson, M.; Khriachtchev, L.; Jolkkonen, S.; Rasanen, M., Photochemistry of HNCO in Solid Xe: Channels of UV Photolysis and Creation of H, J. Phys. Chem. A, 1999, 103, 45, 9154, https://doi.org/10.1021/jp992224d . [all data]

Bolman, Brown, et al., 1975
Bolman, P.S.H.; Brown, J.M.; Carrington, A.; Kopp, I.; Ramsay, D.A., A Re-Investigation of the Formula Formula-Formula Formula Band System of NCO, Proc. Roy. Soc. (London) A343, 1975, 343, 1632, 17, https://doi.org/10.1098/rspa.1975.0050 . [all data]

Gillett, Cooksy, et al., 2006
Gillett, D.A.; Cooksy, A.L.; Brown, J.M., Infrared laser magnetic resonance spectroscopy of the «nu»3 fundamental and associated hot bands of the NCO free radical, J. Mol. Spectrosc., 2006, 239, 2, 190, https://doi.org/10.1016/j.jms.2006.07.005 . [all data]

Barnes, Brown, et al., 1982
Barnes, C.E.; Brown, J.M.; Fackerell, A.D.; Sears, T.J., The laser magnetic resonance spectrum of the NCO radical at 5.2 «mu»m, J. Mol. Spectrosc., 1982, 92, 2, 485, https://doi.org/10.1016/0022-2852(82)90117-5 . [all data]

Bruggemann, Petri, et al., 1989
Bruggemann, R.; Petri, M.; Fischer, H.; Mauer, D.; Reinert, D.; Urban, W., Computer controlled diode laser spectrometer with a helium evaporation cryostat and spectroscopy of thev 3 vibration of NCO, Appl. Phys. B, 1989, 48, 2, 105, https://doi.org/10.1007/BF00692134 . [all data]

Northrup, Wu, et al., 1992
Northrup, F.J.; Wu, M.; Sears, T.J., Measurement of (00v3) levels in X 2«PI» NCO by stimulated emission pumping spectroscopy, J. Chem. Phys., 1992, 96, 10, 7218, https://doi.org/10.1063/1.462426 . [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]

Carrington, Fabris, et al., 1968
Carrington, A.; Fabris, A.R.; Lucas, N.J.D., Electron Resonance Spectrum of NCO in the Gas Phase, J. Chem. Phys., 1968, 49, 12, 5545, https://doi.org/10.1063/1.1670088 . [all data]

Saito and Amano, 1970
Saito, S.; Amano, T., Microwave spectrum of the NCO radical, J. Mol. Spectrosc., 1970, 34, 3, 383, https://doi.org/10.1016/0022-2852(70)90021-4 . [all data]

Amano and Hirota, 1972
Amano, T.; Hirota, E., Hyperfine Interactions of the Free NCO Radical in the «DELTA» Vibronic State (v2 = 1), J. Chem. Phys., 1972, 57, 12, 5608, https://doi.org/10.1063/1.1678265 . [all data]

Reisler, Mangir, et al., 1980
Reisler, H.; Mangir, M.; Wittig, C., The kinetics of free radicals generated by IR laser photolysis. II. Reactions of C2(X 1«SIGMA»+g), C2(a 3«PI»u), C3(X 1«SIGMA»+g) and CN(X 2«SIGMA»+) with O2, Chem. Phys., 1980, 47, 1, 49, https://doi.org/10.1016/0301-0104(80)80019-X . [all data]

Hancock and Ketley, 1982
Hancock, G.; Ketley, G.W., J. Chem. Soc., 1982, Faraday Trans. 2 78, 1283. [all data]

Charlton, Okamura, et al., 1982
Charlton, T.R.; Okamura, T.; Thrush, B.A., Laser-induced fluorescence of NCO in the gas phase, Chem. Phys. Lett., 1982, 89, 2, 98, https://doi.org/10.1016/0009-2614(82)83381-2 . [all data]

Sullivan, Smith, et al., 1983
Sullivan, B.J.; Smith, G.P.; Crosley, D.R., Lifetimes in the B2«PI»i state and the heat of formation of NCO, Chem. Phys. Lett., 1983, 96, 3, 307, https://doi.org/10.1016/0009-2614(83)80678-2 . [all data]

Kawaguchi, Saito, et al., 1985
Kawaguchi, K.; Saito, S.; Hirota, E., Microwave spectroscopy of the NCO radical in the «nu», Mol. Phys., 1985, 55, 2, 341, https://doi.org/10.1080/00268978500101371 . [all data]

Misra, Mathews, et al., 1988
Misra, P.; Mathews, C.W.; Ramsay, D.A., Analysis of the band of 14NCO and 15NCO, J. Mol. Spectrosc., 1988, 130, 2, 419, https://doi.org/10.1016/0022-2852(88)90088-4 . [all data]

Davies and Davis, 1990
Davies, P.B.; Davis, I.H., Far infrared L.M.R. of, Mol. Phys., 1990, 69, 1, 175, https://doi.org/10.1080/00268979000100121 . [all data]

Patel-Misra, Sauder, et al., 1991
Patel-Misra, D.; Sauder, D.G.; Dagdigian, P.J.; Crosley, D.R., Comment on: Observation of highly excited bending levels in NCO(X 2 «PI»), J. Chem. Phys., 1991, 95, 3, 2222, https://doi.org/10.1063/1.460976 . [all data]

Hoops, Bise, et al., 2001
Hoops, A.A.; Bise, R.T.; Gascooke, J.R.; Neumark, D.M., State-resolved translation energy distributions for NCO photodissociation, J. Chem. Phys., 2001, 114, 20, 9020, https://doi.org/10.1063/1.1369132 . [all data]


Notes

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, NIST Free Links, References