Core and Valence Electron Binding Energies of FeI2 and Stabilities of Gas Phase Species

1984 ◽  
Vol 88 (1) ◽  
pp. 65-71 ◽  
Author(s):  
M. Grade ◽  
W. Rosinger ◽  
P. A. Dowben
Keyword(s):  
Gas Phase ◽  
Valence Electron ◽  
Binding Energies ◽  
Electron Binding Energies ◽  
Electron Binding

scholarly journals Electronic Spectroscopy of Isolated DNA Polyanions

2018 ◽  
Author(s):  
Steven Daly ◽  
Massimiliano Porrini ◽  
Frédéric Rosu ◽  
Valerie Gabelica
Keyword(s):  
Gas Phase ◽  
Absorption Spectra ◽  
Ion Mobility ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Action Spectroscopy ◽  
Action Spectra ◽  
Vis Spectroscopy ◽  
Electron Binding Energies ◽  
Electron Binding

In solution, UV-vis spectroscopy is often used to investigate structural changes in biomolecules (i.e., nucleic acids), owing to changes in the environment of their chromophores (i.e., the nucleobases). Here we address whether action spectroscopy could achieve the same for gas-phase ions, while taking the advantage of additional mass spectrometry and ion mobility separation of complex mixtures. We therefore systematically studied the action spectroscopy of homo-base 6-mer DNA strands (dG6, dA6, dC6, dT6), and discuss the results in light of gas-phase structures validated by ion mobility spectrometry and infrared ion spectroscopy, and in light of electron binding energies measured by photoelectron spectroscopy, and calculated electronic photo-absorption spectra. When UV photons interact with oligonucleotide polyanions, two main actions may take place: (1) fragmentation and (2) electron detachment. The action spectra reconstructed from fragmentation follow the absorption spectra well, and result from multiple cycles of absorption and internal conversion. The action spectra reconstructed from the electron photodetachment (EPD) efficiency reveal interesting phenomena: EPD depends on the charge state in a manner depending on electron binding energies, and is particularly efficient for purines but not pyrimidines. EPD thus reflects not only absorption, but also particular relaxation pathways of the electronic excited states. As these pathways lead to photo-oxidation, their investigation on model gas-phase systems may prove useful to elucidate mechanisms of photo-oxidative damages, which are linked to mutations and cancers.

Role of symmetry restrictions on valence electron binding energies of CF4

1980 ◽  
Vol 72 (4) ◽  
pp. 2587-2590 ◽  
Author(s):  
Jiri Müller ◽  
Enrique Poulain ◽  
Osvaldo Goscinski ◽  
Leif Karlsson
Keyword(s):  
Valence Electron ◽  
Binding Energies ◽  
Electron Binding Energies ◽  
Electron Binding

scholarly journals Electronic Spectroscopy of Isolated DNA Polyanions

2018 ◽  
Author(s):  
Steven Daly ◽  
Massimiliano Porrini ◽  
Frédéric Rosu ◽  
Valerie Gabelica
Keyword(s):  
Gas Phase ◽  
Charge State ◽  
Absorption Spectra ◽  
Action Spectrum ◽  
Binding Energies ◽  
Action Spectroscopy ◽  
Action Spectra ◽  
Vis Spectroscopy ◽  
Electron Binding Energies ◽  
Electron Binding

In solution, UV-vis spectroscopy is often used to investigate structural changes in biomolecules (i.e., nucleic acids), owing to changes in the environment of their chromophores (i.e., the nucleobases). Here we address whether action spectroscopy could achieve the same for gas-phase ions, while taking the advantage of additional spectrometric separation of complex mixtures. We therefore systematically studied the action spectroscopy of homo-base 6-mer DNA strands (dG6, dA6, dC6, dT6) and discuss the results in light of gas-phase structures validated by ion mobility spectrometry and infrared ion spectroscopy, of electron binding energies measured by photoelectron spectroscopy, and of calculated electronic photo-absorption spectra. When UV photons interact with oligonucleotide polyanions, two main actions may take place: (1) fragmentation and (2) electron detachment. The action spectra reconstructed from fragmentation follow the absorption spectra well, and result from multiple cycles of absorption and internal conversion. The action spectra reconstructed from the electron photodetachment (ePD) efficiency reveal interesting phenomena: ePD depends on the charge state because it depends on electron binding energies. We illustrate with the G-quadruplex [dTG4T]4 that the ePD action spectrum shifts with the charge state, pointing to possible caveats when comparing the spectra of systems having different charge densities to deduce structural parameters. Moreover, ePD is particularly efficient for purines but not pyrimidines. ePD thus reflects not only absorption, but also particular relaxation pathways of the electronic excited states. As these pathways lead to photo-oxidation, their investigation on model gas-phase systems may prove useful to elucidate mechanisms of photo-oxidative damages, which are linked to mutations and cancers.

A theoretical investigation of electron relaxation accompanying core ionization in the symmetry forms of ethylene

1982 ◽  
Vol 47 (12) ◽  
pp. 3371-3374
Author(s):  
Tomáš Ficker
Keyword(s):  
Ab Initio ◽  
Theoretical Investigation ◽  
Valence Electron ◽  
Binding Energies ◽  
Core Electron ◽  
The Core ◽  
Electron Relaxation ◽  
Electron Binding Energies ◽  
Electron Binding

Relaxation energies accompanying core ionization in the planar and twisted form of the C2H4 molecule have been computed in terms of single orbital contributions by means of the ab initio SCF techniques. It is shown that the 2 eV shift between the core electron binding energies of both symmetry conformers may be attributed to changes in the π-valence electron relaxation when going from the planar to the twisted form of C2H4.

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