Observation of the infrared spectrum of methyl cation CH+3

Crofton, Mark W.; Kreiner, W. A.; Jagod, M. F.; Rehfuss, B. D.; Oka, Takeshi

doi:10.1063/1.449125

Cited by 50 publications

(24 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the tunneling splitting in the ground vibrational state (Av 5 1 M H z )~~ is much smaller than the resolution of our Doppler-limited spectroscopy, the tunneling effect appears as identical splittings in the corresponding R and P branch 6 We do not see any obvious regularity in the splitting. Sometimes levels are split into more than two components.…”

Section: Table 3: Rotational Constants In the Ground Vibrational Statmentioning

confidence: 92%

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Gabrys¹,

Uy²,

Jagod³

et al. 1995

J. Phys. Chem.

View full text Add to dashboard Cite

The vibration-rotation energy level pattem of protonated acetylene, C2H3+, in the v6 (C-H antisymmetric stretching) vibrational state is anomalous and irregular because of the coupling between the rotational motion and the tunneling of the three protons among their equilibrium positions. The resultant spectral anomaly and the coexistence of C-H bands of other carbocations such as CH3+, C2H2+, CH2+, etc., in our positive column discharge using He-dominated gas mixtures had made the analysis of the C2H3+ spectrum difficult. In the present paper we use a hollow cathode discharge to simplify plasma chemistry and to make a more definitive and extensive analysis of the spectrum. A 3 m hollow cathode discharge cell has been constructed with a multiple reflection optical system giving an effective path length of 30 m. A gas mixture of C2H2 and H2 with pressures of 0.03 and 1.1 Torr, respectively, has produced spectral lines of C2H3' from 3192 to 3083 cm-' which are almost completely free of those from other carbocations. The purity of the spectrum, together with the accurate ground state rotational constants recently reported by the Lille millimeter wave group, has allowed us to assign spectral lines up to J = 25 and K, = 4 and to determine extensive sets of the A-E splittings due to the proton tunneling in the excited state. An attempt has been made to analyze the plasma chemistry in the hollow cathode on the basis of earlier plasma diagnostic studies of the negative glow region. A model was used in which the primary molecular ions H2+ and C2H2+ are generated due to ionization by "hot" primary and secondary electrons. In the plasma these ions undergo ion-neutral reactions to produce H3+ and C2H3+, which are dissociated by reactions with C2H2 and recombination with "ultimate" electrons. By assuming proper number densities of primary, secondary, and ultimate electrons, semiquantitative agreement with the experimentally estimated ion densities has been obtained.

show abstract

Section: Table 3: Rotational Constants In the Ground Vibrational Statmentioning

confidence: 92%

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Gabrys¹,

Uy²,

Jagod³

et al. 1995

J. Phys. Chem.

View full text Add to dashboard Cite

show abstract

“…The ionization of CH 4 and CD 4 should be the initial step of the formation processes. Energetically all CH + can be generated (Crofton et al 1985). The …”

Section: Experimental Procedures and Resultsmentioning

confidence: 99%

Submillimeter-wave spectrum of CH₂D⁺

Amano

2010

A&A

View full text Add to dashboard Cite

Aims. Recently a tentative identification of CH 2 D+ in interstellar space has been reported. To facilitate astronomical identifications, laboratory measurements of precise rest frequencies for the rotational lines of CH 2 D + should be carried out. Methods. A submillimeter-wave spectrometer is used for detection of CH 2 D + . The CH 2 D + ion is generated in an extended negative glow discharge operated at liquid nitrogen temperature. The optimum gas mixture is found to be CH 4 (∼3 mTorr), CD 4 (∼1 mTorr), and H 2 (∼2 mTorr) in helium buffer. Results. Four rotational lines have been detected in the frequency range of 280−890 GHz. The measured frequencies agree very well within a MHz with the predictions given by Rösslein et al. from the infrared spectra. Conclusions. Two rotational lines of this ion have been tentatively identified toward Ori IRc2. The rest frequencies obtained here should facilitate identifications and analysis of astronomical spectra.

show abstract

“…Despite its importance, there is a lack of high resolution spectroscopic data for CH þ 3 primarily because of its polymerization in discharges [195]. Oka and co-workers [195][196][197] observed the accurate frequency of the degenerate C-H stretch ( 3 ) by infrared spectroscopy. There have also been reports [198][199][200][201] on the frequencies of the umbrella (out-of-plane or OPLA) Table 11.…”

Section: Chmentioning

confidence: 98%

Anharmonic vibrational frequencies and vibrationally-averaged structures of key species in hydrocarbon combustion: HCO⁺, HCO, HNO, HOO, HOO^–, CH₃ ⁺, and CH₃

et al. 2009

View full text Add to dashboard Cite

A general scheme to predict anharmonic vibrational frequencies and vibrationally-averaged structures and rotational constants of molecules is presented with applications to some key species in hydrocarbon combustion (some also of importance in atmospheric and/or interstellar chemistry): HCO þ , HCO, HNO, HOO, HOO -,CH þ 3 , and CH 3 . A combination of coupled-cluster singles and doubles (CCSD), CCSD with a second-order perturbation correction in the space of triples [CCSD(2) T ] and in the space of triples and quadruples [CCSD(2) TQ ], and a correlation-consistent basis set series has been employed to achieve the complete-correlation, complete-basis-set limits of the potential energy surfaces (PESs) of these species near equilibrium geometries. A new, compact representation of PESs that combines two existing representations, namely, a fourth-order Taylor expansion and numerical values on a rectilinear grid, has been proposed and shown to yield accurate frequencies, when combined with vibrational general-order configuration-interaction method. The predicted frequencies (and the observed in parentheses, when available) of the fundamentals are as follows: 823 3139 (3161) cm À1 in CH 3 . The mean absolute deviation in the predicted frequencies is 11 cm À1 .

show abstract

Observation of the infrared spectrum of methyl cation CH+3

Cited by 50 publications

References 10 publications

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Submillimeter-wave spectrum of CH₂D⁺

Anharmonic vibrational frequencies and vibrationally-averaged structures of key species in hydrocarbon combustion: HCO⁺, HCO, HNO, HOO, HOO^–, CH₃ ⁺, and CH₃

Contact Info

Product

Resources

About

Observation of the infrared spectrum of methyl cation CH+3

Cited by 50 publications

References 10 publications

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Infrared Spectroscopy of Carboions. 8. Hollow Cathode Spectroscopy of Protonated Acetylene, C2H3+

Submillimeter-wave spectrum of CH2D+

Anharmonic vibrational frequencies and vibrationally-averaged structures of key species in hydrocarbon combustion: HCO+, HCO, HNO, HOO, HOO–, CH3 +, and CH3

Contact Info

Product

Resources

About

Submillimeter-wave spectrum of CH₂D⁺

Anharmonic vibrational frequencies and vibrationally-averaged structures of key species in hydrocarbon combustion: HCO⁺, HCO, HNO, HOO, HOO^–, CH₃ ⁺, and CH₃