Calculation of the abundance ratio [] from n-butylbenzene molecular ions as a function of internal energy

1981 ◽  
Vol 41 (1-2) ◽  
pp. 83-88 ◽  
Author(s):  
I.W. Griffiths ◽  
F.M. Harris ◽  
E.S. Mukhtar ◽  
J.H. Beynon
Keyword(s):  
Internal Energy ◽  
Abundance Ratio ◽  
Molecular Ions

High-resolution infrared spectroscopy of molecular ions

1988 ◽  
Vol 324 (1578) ◽  
pp. 163-178 ◽  
Keyword(s):  
Infrared Spectroscopy ◽  
High Resolution ◽  
Rate Equation ◽  
Abundance Ratio ◽  
Reaction Scheme ◽  
Molecular Ions ◽  
Infrared Absorption Spectroscopy ◽  
Fundamental Band ◽  
Ion Spectroscopy ◽  
Equation Analysis

Experimental techniques of high-resolution infrared absorption spectroscopy are described with an emphasis on the modulated hollow-cathode discharge techniques. Among the recent results, the rq fundamental band of HOCS+ |iq — 3435.16 cm-1) and the X2IT and a4E” system of NH+ (t0 = 2903.17 cm-1 in X2II state, = 2544.30 cm-1 in a4E~ state, and A£(a4E_ —X2n) — 323.90 cm-1) are presented to illustrate the quality and type of information that the high-resolution ion spectroscopy can provide. Another topic discussed is the abundance ratio [HCO+]/[H O C +] as measured in the laboratory and its astrophysics implications. The measurement has been made possible by our recent detection of the rq fundamental band of HOC+ (iq, — 3268.03 cm""1). A rate-equation analysis was performed by assuming a reaction scheme to derive the rate constants of several key reactions.

Appearance Potentials of Metastable Molecular Ions

1967 ◽  
Vol 22 (1) ◽  
pp. 40-47 ◽  
Author(s):  
I. Hertel ◽  
Ch. Ottinger
Keyword(s):  
Internal Energy ◽  
Rate Constant ◽  
Molecular Ions ◽  
Energy Scale ◽  
Constant Density ◽  
Fragment Ions ◽  
Linear Threshold ◽  
Primary Fragmentation ◽  
Order Of Magnitude ◽  
Slow Rise

Differences between the appearance potentials of fragment ions formed a few μ secs after the ionization (so-called metastables) and normal fragment ions were measured. It is shown, however, that no immediate meaning regarding the primary fragmentation mechanism can be attached to these quantities. Instead, the experimental ionization curves of metastable and normal fragments were explained by a theoretical model which assumes 1) a linear threshold law, 2) a linear relation between the logarithm of the rate constant and the internal energy in the molecular ion, and 3) a constant density of populated states on the energy scale. In the case of HCN loss from benzonitrile ions, an excellent fit between the experimental and theoretical curves can then be achieved if it is assumed that an increase of 0.65 eV internal energy increases the rate constant by one order of magnitude. This is a surprisingly slow rise of k (E), compared with the few existing calculations in other cases.

Internal energy effects in the reactivity of CO22+ doubly charged molecular ions with CO2 and CO

2003 ◽  
Vol 228 (2-3) ◽  
pp. 507-516 ◽  
Author(s):  
Pietro Franceschi ◽  
Roland Thissen ◽  
Ján Žabka ◽  
Jana Roithová ◽  
Zdenek Herman ◽  
...  
Keyword(s):  
Internal Energy ◽  
Molecular Ions ◽  
Doubly Charged

Appearance Energies and Calculated Partial Mass Spectra of (23-), (2,4-) and (2,5-)Dimethylaniline Isomers

1983 ◽  
Vol 38 (10) ◽  
pp. 1084-1087 ◽  
Author(s):  
F. H. Abd El-Kader ◽  
H. M. Ahmed
Keyword(s):  
Energy Range ◽  
Internal Energy ◽  
Energy Dependence ◽  
Mass Spectra ◽  
Critical Energy ◽  
Molecular Ions ◽  
Fragment Ions ◽  
Kinetic Shift

Abstract The ionization and appearance energies for the molecular and fragment ions, respectively, of the three dimethylaniline isomers are reported. Breakdown graphs have been constructed expressing the energy dependence of the fragmentation of the isomeric molecular ions covering the internal energy range from threshold to approximately 10 eV. The kinetic shift and the critical energy for the fragments (M-H)+ and (M-CH3)+ ions are also calculated.

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