C6H2+

Formula: C₆H₂⁺
Molecular weight: 74.0795
CAS Registry Number: 61866-06-6
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Vibrational and/or electronic energy levels

State: D

Energy (cm^-1)	Med.	References


T_o = 27350 ± 160	gas	Brogli, Heilbronner, et al., 1973

cm^-1	Med.	Method	References


650 ± 80	gas	PE	Brogli, Heilbronner, et al., 1973

State: C

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 23969 ± 12	Ne	C-X	381	418	Fulara, Grutter, et al., 2007

Vib. sym.	No.	cm^-1	Med.	Method	References


Σ_g⁺	2	2278 ± 18	Ne	AB	Fulara, Grutter, et al., 2007
	4	662 ± 18	Ne	AB	Fulara, Grutter, et al., 2007

State: A

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 16654.69	gas	A-X	485	725	Allan, Kloster-Jensen, et al., 1976
					Klapstein, Kuhn, et al., 1984
					Sinclair, Pfluger, et al., 1999
					Pfluger, Sinclair, et al., 1999
					Dzhonson, Jochnowitz, et al., 2007
T_o = 16570	Ne	A-X	524	843	Smith, Agreiter, et al., 1994
					Freivogel, Fulara, et al., 1994

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


Σ_g⁺	1	CH stretch	3243 ± 2	T	gas	LF	Klapstein, Kuhn, et al., 1984
	2	CC stretch	2053 ± 2		gas	LF	Klapstein, Kuhn, et al., 1984
	2	CC stretch	2065.7		Ne	LF AB	Smith, Agreiter, et al., 1994 Freivogel, Fulara, et al., 1994
	3	CC stretch	1880 ± 2		gas	LF	Klapstein, Kuhn, et al., 1984
	3	CC stretch	1890.2		Ne	LF AB	Smith, Agreiter, et al., 1994 Freivogel, Fulara, et al., 1994
	4	C-C stretch	617.8		gas	LF AB	Allan, Kloster-Jensen, et al., 1976 Klapstein, Kuhn, et al., 1984 Pfluger, Sinclair, et al., 1999
	4	C-C stretch	630		Ne	LF AB	Smith, Agreiter, et al., 1994 Freivogel, Fulara, et al., 1994
Π_g	10	Skel. bend	244	T	gas	LF	Klapstein, Kuhn, et al., 1984
	10	Skel. bend	248	H	Ne	LF	Smith, Agreiter, et al., 1994

State: X

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


Σ_g⁺	2	CC stretch	2182 ± 2		gas	EF	Allan, Kloster-Jensen, et al., 1976 Klapstein, Kuhn, et al., 1984
	2	CC stretch	2181.4		Ne	LF	Smith, Agreiter, et al., 1994
	3	CC stretch	1903 ± 2		gas	EF	Allan, Kloster-Jensen, et al., 1976 Klapstein, Kuhn, et al., 1984
	3	CC stretch	1903.4		Ne	LF	Smith, Agreiter, et al., 1994
	4	C-C stretch	632 ± 2		gas	EF	Allan, Kloster-Jensen, et al., 1976 Klapstein, Kuhn, et al., 1984
	4	C-C stretch	635	H	Ne	LF	Smith, Agreiter, et al., 1994
Σ_u⁺	6	CC stretch	2014	T	Ne	LF	Smith, Agreiter, et al., 1994
Π_g	10	Skel. bend	228 ± 2	T	gas	LF	Klapstein, Kuhn, et al., 1984
	10	Skel. bend	230	T	Ne	LF	Smith, Agreiter, et al., 1994

Additional references: Jacox, 1994, page 380; Jacox, 1998, page 339; Jacox, 2003, page 358

Notes

(1/2)(2ν)

Tentative assignment or approximate value

Energy separation between the v = 0 levels of the excited and electronic ground states.

References

Go To: Top, Vibrational and/or electronic energy levels, Notes

Brogli, Heilbronner, et al., 1973
Brogli, F.; Heilbronner, E.; Hornung, V.; Kloster-Jensen, E., 230. Die photoelektronen-spektren methyl-substituierter Acetylene, Helv. Chim. Acta, 1973, 56, 2171. [all data]

Fulara, Grutter, et al., 2007
Fulara, J.; Grutter, M.; Maier, J.P., Higher Excited Electronic Transitions of Polyacetylene Cations HC, J. Phys. Chem. A, 2007, 111, 46, 11831, https://doi.org/10.1021/jp075807t . [all data]

Allan, Kloster-Jensen, et al., 1976
Allan, M.; Kloster-Jensen, E.; Maier, J.P., Emission spectra of the radical cations of diacetylene (Ã2Πu→X2Πg), triacetylene (Ã2Πg→X2Πu), and tetraacetylene (Ã2Πu→X2Πg,O00), and the lifetimes of some vibronic levels of the Ã states, Chem. Phys., 1976, 17, 1, 11, https://doi.org/10.1016/0301-0104(76)85002-1 . [all data]

Klapstein, Kuhn, et al., 1984
Klapstein, D.; Kuhn, R.; Maier, J.P.; Ochsner, M.; Zambach, W., Emission and laser excitation spectra of the ~A2.PI.u .tautm. ~X2.PI.g transition of rotationally cooled triacetylene cation, J. Phys. Chem., 1984, 88, 22, 5176, https://doi.org/10.1021/j150666a012 . [all data]

Sinclair, Pfluger, et al., 1999
Sinclair, W.E.; Pfluger, D.; Linnartz, H.; Maier, J.P., Rotationally resolved A [sup 2]Π[sub g]←X [sup 2]Π[sub u] electronic spectrum of triacetylene cation by frequency modulation absorption spectroscopy, J. Chem. Phys., 1999, 110, 1, 296, https://doi.org/10.1063/1.478065 . [all data]

Pfluger, Sinclair, et al., 1999
Pfluger, D.; Sinclair, W.E.; Linnartz, H.; Maier, J.P., Rotationally resolved electronic absorption spectra of triacetylene cation in a supersonic jet, Chem. Phys. Lett., 1999, 313, 1-2, 171, https://doi.org/10.1016/S0009-2614(99)00984-7 . [all data]

Dzhonson, Jochnowitz, et al., 2007
Dzhonson, A.; Jochnowitz, E.B.; Maier, J.P., Electronic Gas-Phase Spectra of Larger Polyacetylene Cations, J. Phys. Chem. A, 2007, 111, 10, 1887, https://doi.org/10.1021/jp067439j . [all data]

Smith, Agreiter, et al., 1994
Smith, A.M.; Agreiter, J.; Hartle, M.; Engel, C.; Bondybey, V.E., Rare gas matrix studies of absorption and fluorescence of reactive intermediates formed in discharges through acetylene, Chem. Phys., 1994, 189, 2, 315, https://doi.org/10.1016/0301-0104(94)00299-1 . [all data]

Freivogel, Fulara, et al., 1994
Freivogel, P.; Fulara, J.; Lessen, D.; Forney, D.; Maier, J.P., Absorption spectra of conjugated hydrocarbon cation chains in neon matrices, Chem. Phys., 1994, 189, 2, 335, https://doi.org/10.1016/0301-0104(94)00243-6 . [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]

Notes

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

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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