Adiabatic ionization energies of the overlapped A2A1 and B2E electronic states in CH3Cl+/CH3F+ measured with double imaging electron/ion coincidence

2015 ◽  
Vol 17 (26) ◽  
pp. 16858-16863 ◽  
Author(s):  
Xiaofeng Tang ◽  
Gustavo A. Garcia ◽  
Laurent Nahon
Keyword(s):  
Kinetic Energy ◽  
Electronic States ◽  
Correlation Diagram ◽  
Energy Correlation ◽  
Ionization Energies ◽  
Dissociation Dynamics ◽  
Ion Kinetic Energy

The overlapped A2A1 and B2E electronic states of CH3Cl+ have been separated and their adiabatic ionization energies have been measured from an electron and ion kinetic energy correlation diagram based on their different dissociation dynamics.

VUV FRAGMENTATION OF SOME HYDROFLUOROCARBON CATIONS STUDIED USING COINCIDENCE TECHNIQUES

2002 ◽  
Vol 09 (01) ◽  
pp. 153-158 ◽  
Author(s):  
WEIDONG ZHOU ◽  
D. P. SECCOMBE ◽  
R. Y. L. CHIM ◽  
R. P. TUCKETT
Keyword(s):  
Kinetic Energy ◽  
Ab Initio ◽  
Ground State ◽  
Lower Energy ◽  
Lone Pair ◽  
Electronic States ◽  
Photoelectron Spectra ◽  
Highest Occupied Molecular Orbital ◽  
Impulsive Model ◽  
Lone Pair Electrons

Threshold photoelectron–photoion coincidence (TPEPICO) spectroscopy has been used to investigate the decay dynamics of the valence electronic states of the parent cation of several hydrofluorocarbons (HFC), based on fluorine-substituted ethane, in the energy range 11–25 eV. We present data for CF 3– CHF 2, CF 3– CH 2 F , CF 3– CH 3 and CHF 2– CH 3. The threshold photoelectron spectra (TPES) of these molecules show a common feature of a broad, relatively weak ground state, associated with electron removal from the highest-occupied molecular orbital (HOMO) having mainly C–C σ-bonding character. Adiabatic and vertical ionisation energies for the HOMO of the four HFCs are presented, together with corresponding values from ab initio calculations. For those lower-energy molecular orbitals associated with non-bonding fluorine 2pπ lone pair electrons, these electronic states of the HFC cation decay impulsively by C–F bond fission with considerable release of translational kinetic energy. Appearance energies are presented for formation of the daughter cation formed by such a process (e.g. CF 3– CHF +), together with ab initio energies of the corresponding dissociation channel (e.g. CF 3– CHF + + F ). Values for the translational kinetic energy released are compared with the predictions of a pure-impulsive model.

Ion Kinetic Energy Determinations in Radio-Frequency Glow Discharge Mass Spectrometry

1995 ◽  
Vol 49 (7) ◽  
pp. 917-926 ◽  
Author(s):  
Paula R. Cable ◽  
R. Kenneth Marcus
Keyword(s):  
Kinetic Energy ◽  
Glow Discharge ◽  
Radio Frequency ◽  
Source Region ◽  
Potential Method ◽  
Operating Conditions ◽  
Atmospheric Plasma ◽  
Radio Frequency Glow Discharge ◽  
Ion Trajectory ◽  
Ion Kinetic Energy

Radio-frequency glow discharge (rf-GD) sources produce an abundance of both atoms and ions. For the mass spectrometric application of the glow discharge technique, knowledge of the ion kinetic energies is required to optimize extraction and focusing of ions from the source region into the analyzer. This paper details kinetic energies experimentally determined with the use of the “retarding potential” method. For this study, the analyzer quadrupole of a double-quadrupole mass spectrometer was positively biased to act as a repeller. Ion kinetic energies (IKEs) determined for a variety of discharge and analyzer operating conditions ranged from 12.5 eV to 25.0 eV for 63Cu+. Kinetic energy measurements were confirmed from ion trajectory simulations and follow closely the experimental values for identical analyzer conditions and initial IKEs. Results of this study indicate that the conditions under which ions are formed (plasma conditions) affect IKEs and energy spreads to a greater extent than analyzer parameter variations. Different from atmospheric plasma sources, IKEs for rf-GD species do not vary as a function of ion mass/identity. Evidence is also given in support of a slight mass biasing owing to the transmission properties of double-quadrupole analyzers. The findings detailed herein demonstrate the effects of rf modulation on both ion kinetic energy values and distributions.

Application of mass-analysed ion kinetic energy spectrometry (MIKES) to the determination of the structures of unknown compounds

The Analyst ◽  
1978 ◽  
Vol 103 (1227) ◽  
pp. 613 ◽  
Author(s):  
M. H. Bozorgzadeh ◽  
R. P. Morgan ◽  
J. H. Beynon
Keyword(s):  
Kinetic Energy ◽  
Ion Kinetic Energy
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