Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 7.—The methyl radical

Dyke, John M.; Jonathan, Neville; Lee, Edmond; Morris, Alan

doi:10.1039/f29767201385

Cited by 143 publications

(71 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The first band of the methyl radical, which was observed as a secondary reaction product, was also used for calibration. 12 The largest impurity to the He I a radiation from the helium discharge lamp used10 was He I@ radiation (23.08 eV) which had approximately 1% the intensity of the He Ia radiation. This He I@ radiation forms a weak "shadow spectrum' in the He I a spectrum with an apparent shift of 1.87 eV to lower ionization energy (as measured on the He Ia ionization energy scale).…”

Section: Methodsmentioning

confidence: 99%

A study of the fluorine atom + dimethyl disulfide reaction by photoelectron spectroscopy, supported by ab initio molecular orbital calculations

Baker¹,

Dyke²

1994

J. Phys. Chem.

View full text Add to dashboard Cite

The F + CH3SSCH3 reaction has been studied by He I photoelectron spectroscopy and is seen to proceed via two competing routes, a hydrogen atom abstraction channel to generate the CHsSSCHz radical, and an adduct channel, where the adduct unimolecularly decomposes to generate CH3SF and CH3S. A weak broad band with adiabatic and vertical ionization energies of 7.00 & 0.07 eV and 7.45 f 0.03 eV, respectively, appearing at short reaction times, has been assigned to the first photoelectron band of CH3SSCH2. Two other photoelectron bands appearing early in the reaction, with measured adiabatic ionization energies of 9.26 f 0.03 eV and = 9.4 eV have been assigned to the CH3S radical and tentatively to CH$F, respectively. SF2 and CH3 are also observed in the reaction and are explained as the products of the secondary reaction F + CHsSF. Ab initio calculations which include full geometry optimizations have been performed on CH3SSCH2 and CHsSF and their lowestlying cationic states, and the adiabatic and vertical ionization energies obtained are consistent with the above assignments. The structures and bonding in CH3SSCH2 and CH3SF and their cations are also discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

A study of the fluorine atom + dimethyl disulfide reaction by photoelectron spectroscopy, supported by ab initio molecular orbital calculations

Baker¹,

Dyke²

1994

J. Phys. Chem.

View full text Add to dashboard Cite

show abstract

“…ionization energies in Ref. 33) is either not formed in predissociation of the 2a l -, state or is subject to further decay processes.…”

Section: Discussion Of Potential Curvesmentioning

confidence: 99%

X-ray, ultraviolet, and synchrotron radiation excited inner-valence photoelectron spectra of CH4

Göthe

Wannberg

Karlsson

et al. 1991

The Journal of Chemical Physics

View full text Add to dashboard Cite

The inner-valence electron states of the methane molecule have been studied by means of x-ray, synchrotron radiation, and UV-photoelectron spectroscopy. Five correlation satellites have been identified and a detailed study has been carried out of the 2a−11 single hole state. For this state a Franck–Condon analysis has been performed, suggesting an equilibrium bond distance of 1.279 Å. The vibrational lines have a Lorentzian shape and the linewidth increases gradually with the vibrational quantum number. This probably indicates a reduction of the lifetime of the vibrational states due to predissociation. A discussion of the potential curves related to the correlation satellites is included.

show abstract

“…In the latter case the electronic excitation of the Br atom has to be discarded: the first excited state 4 P 5/2 lies at 63,429 cm -1 above the 2 P 3/2 ground state [35]. On the other hand, the excitation of the CH 3 + ion in its A 3 E" and Ã 1 E// states requires 4.92 and 6.26 eV, respectively [43]. Below 20 eV only the excitation of CH 3 + in its a 3 E" state could be considered and large amounts of translational energy have to be involved.…”

Section: The Chf Fragment Ion (See Figs 5(b) and 6)mentioning

confidence: 99%

About the photoionization of methyl bromide (CH3Br). Photoelectron and photoionization mass spectrometric investigation

et al. 2006

View full text Add to dashboard Cite

The threshold photoelectron (TPES) and the photoionization mass spectrometric study of CH 3 Br in the 8-20 eV photon energy range is presented. The interpretation and assignments are supported by ab initio calculations. The TPES shows several new discrete features in the Jahn-Teller split ground state X 2 E( 2 A'-2 A") of CH 3 Br + . An additional continuous band starts at about 11.8 eV. These observations are both correlated with direct ionization and autoionizing transitions. This is supported by constant ion state (CIS) spectroscopy. A large enhancement of the transitions to the A 2 A and B E states is ascribed to important autoionizing contributions. Based on the present calculations, the weak to very weak bands in the 17.5-22.0 eV photon energy range were mainly assigned to 2a 1 -1 ionization and to double excitations described essentially by the 2e -2 4a 1 1 and le -1 2e -1 4a 1 1 configurations. The photoionization mass spectrometric study allowed us to investigate in detail the ionization and dissociation of CH 3 Br + leading to CH 2 + , CH 3 + , Br + and CH 2 Br + from threshold up to 20 eV photon energy. The experimental data are compared to ab initio dissociation energies. At the onset, the CH 3 + and CH 2 Br + fragment ion production is correlated with the ground state of CH 3 Br + and both fragment ions have to appear through dissociative autoionization from the (3a 1 1 /1e 3 )6s or 5s Rydberg state. This interpretation is supported by the photoabsorption spectrum measured recently in the same photon energy range. At higher energies, beside a likely direct (pre)dissociation of the Ã 2 A 1 and B 2 E states of CH 3 Br + , autoionization also contributes to the fragmentation in all decay channels. Avoided crossings in a manifold of 2 A' states are likely to be involved. This is supported by ab initio calculations. For CH 3 + the photoion-pair process is analyzed and detailed assignments are proposed on the basis of our latest VUV photoabsorption spectroscopic data.

show abstract

Vacuum ultraviolet photoelectron spectroscopy of transient species. Part 7.—The methyl radical

Cited by 143 publications

References 2 publications

A study of the fluorine atom + dimethyl disulfide reaction by photoelectron spectroscopy, supported by ab initio molecular orbital calculations

A study of the fluorine atom + dimethyl disulfide reaction by photoelectron spectroscopy, supported by ab initio molecular orbital calculations

X-ray, ultraviolet, and synchrotron radiation excited inner-valence photoelectron spectra of CH4

About the photoionization of methyl bromide (CH3Br). Photoelectron and photoionization mass spectrometric investigation

Contact Info

Product

Resources

About