Related Experiment Video
Updated: Aug 7, 2026

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
The double photoionization of hydrogen iodide molecules
M Alagia1, B G Brunetti, P Candori
1ISMN-CNR Sez. Roma 1, P.le A. Moro 5, 00185, Rome, Italy.
Abstract:
The double photoionization of HI molecules has been investigated using vacuum ultraviolet synchrotron radiation in the energy range between 27 and 35 eV. The product ions have been detected by the use of time-of-flight mass spectrometry and the threshold energy for HI2+ and H+ + I+ formation has been determined. These results have been interpreted by the use of a theoretical model which has been previously applied by us to HBr2+ and HCl2+. On the basis of the reliability of such a model, an assessment of the systematic trends of the bond features along the HX2+ (X=F, Cl, Br, I) homologous series is given in this paper. In particular, the increase of the stability of these dications, in their lowest electronic states, when going towards the heavier molecules, has been rationalized considering the systematic variation of the charge transfer coupling between the H-X2+ and the H+-X+ states.
More Related Videos
Related Concept Videos
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
Hess's Law
Hybridization of Atomic Orbitals I
Chemical Ionization (CI) Mass Spectrometry
Hybridization of Atomic Orbitals II
IR Absorption Frequency: Hybridization
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...

