Resonant states at threshold observed in electron photodetachment cross sections of polyatomic negative ions

1979 ◽  
Vol 71 (5) ◽  
pp. 2088 ◽  
Author(s):  
Robert L. Jackson ◽  
Albert H. Zimmerman ◽  
John I. Brauman
Keyword(s):  
Cross Sections ◽  
Negative Ions ◽  
Resonant States ◽  
Electron Photodetachment

scholarly journals Mass-resolved electronic circular dichroism ion spectroscopy

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1465-1468 ◽  
Author(s):  
Steven Daly ◽  
Frédéric Rosu ◽  
Valérie Gabelica
Keyword(s):  
Circular Dichroism ◽  
Three Dimensional ◽  
Polarized Light ◽  
Negative Ions ◽  
Data Interpretation ◽  
Electronic Circular Dichroism ◽  
Circularly Polarized Light ◽  
Chiral Compounds ◽  
Electron Photodetachment ◽  
Circular Dichroïsm

DNA and proteins are chiral: Their three-dimensional structures cannot be superimposed with their mirror images. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We studied guanine-rich strands having various secondary structures, electrosprayed them as negative ions, irradiated them with an ultraviolet nanosecond optical parametric oscillator laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resembled those of their solution-phase counterparts, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.

Photoablösung von Elektronen bei einigen stabilen negativen Ionen

1970 ◽  
Vol 25 (5) ◽  
pp. 621-626 ◽  
Author(s):  
D. Feldmann
Keyword(s):  
Cross Sections ◽  
Negative Ions ◽  
Better Than

Photodetaehment of electrons from some stable negative ions has been measured. Cross sections of about 10-17 cm2, and the following minimal detachment energies were found: H-: 0.776 eV, C-*: < 0.5 eV, CH-: 0.74 eV, C2- : 3.54 eV, C2H- : 3.73 eV, SO-: 1.09 eV, and SO-: 1.0 eV with an accuracy better than + 0.05 eV.

Capture Cross Sections for Negative Ions in Rotating Helium II

1965 ◽  
Vol 14 (15) ◽  
pp. 585-587 ◽  
Author(s):  
B. E. Springett ◽  
D. J. Tanner ◽  
R. J. Donnelly
Keyword(s):  
Cross Sections ◽  
Negative Ions ◽  
Capture Cross ◽  
Helium Ii ◽  
Capture Cross Sections

scholarly journals Single-Photon Multiple Detachment in Fullerene Negative Ions: Absolute Ionization Cross Sections and the Role of the Extra Electron

2013 ◽  
Vol 111 (4) ◽  
Author(s):  
R. C. Bilodeau ◽  
N. D. Gibson ◽  
C. W. Walter ◽  
D. A. Esteves-Macaluso ◽  
S. Schippers ◽  
...  
Keyword(s):  
Cross Sections ◽  
Single Photon ◽  
Negative Ions ◽  
Ionization Cross ◽  
Extra Electron ◽  
Ionization Cross Sections

Measurement of the three-photon detachment cross sections of the negative ions of iodine, bromine and fluorine at the wavelength 1.0642 mu m

1989 ◽  
Vol 22 (9) ◽  
pp. 1335-1351 ◽  
Author(s):  
C Blondel ◽  
R -J Champeau ◽  
M Crance ◽  
A Crubellier ◽  
C Delsart ◽  
...  
Keyword(s):  
Cross Sections ◽  
Negative Ions

scholarly journals Fullerene Negative Ions: Formation and Catalysis

2020 ◽  
Author(s):  
Zineb Felfli ◽  
Kelvin Suggs ◽  
Nantambu Nicholas ◽  
Alfred Z. Msezane
Keyword(s):  
Transition State ◽  
Cross Sections ◽  
Water Oxidation ◽  
Regge Pole ◽  
Negative Ions ◽  
Negative Ion ◽  
Total Cross Sections ◽  
Hydrogen Bond Strength ◽  
Low Energy Electron ◽  
Fundamental Mechanism

We first explore negative-ion formation in fullerenes C44, C60, C70, C98, C112, C120, C132 and C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Water oxidation to peroxide and water synthesis from H2 and O2 are then investigated using the anionic catalysts C44ˉ to C136ˉ. The fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening in the transition state. DFT transition state calculations found C60ˉ numerically stable for both water and peroxide synthesis, C100ˉ increases the energy barrier the most and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

scholarly journals Resonant states 0+ of the Boron isotope 8B from the Jost-matrix analysis of the partial cross-sections

2019 ◽  
Vol 28 (10) ◽  
pp. 1950083
Author(s):  
S. A. Rakityansky ◽  
S. N. Ershov ◽  
T. J. Tshipi
Keyword(s):  
Experimental Data ◽  
Riemann Surface ◽  
Partial Wave ◽  
Coulomb Interaction ◽  
Cross Sections ◽  
Matrix Analysis ◽  
Analytic Structure ◽  
Square Root ◽  
Excitation Energies ◽  
Resonant States

The available [Formula: see text]-matrix parametrization of experimental data on the excitation functions for the elastic and inelastic [Formula: see text] scattering at the collision energies up to 3.4[Formula: see text]MeV is used to generate the corresponding partial-wave cross-sections in the states with [Formula: see text]. Thus, obtained data are fitted using the semi-analytic two-channel Jost matrix with a proper analytic structure and some adjustable parameters. Then the spectral points are sought as zeros of the Jost matrix determinant (which correspond to the [Formula: see text]-matrix poles) at complex energies. The correct analytic structure makes it possible to calculate the fitted Jost matrix on any sheet of the Riemann surface whose topology involves not only the square-root but also the logarithmic branching caused by the Coulomb interaction. In this way, two overlapping [Formula: see text] resonances at the excitation energies [Formula: see text] and [Formula: see text][Formula: see text]MeV have been found.

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