Threshold effects in I−⋅CH3CN and I−⋅H2O cluster anion detachment: The angular distribution as an indicator of electronic autodetachment

Abstract

I(-) x H(2)O and I(-) x CH(3)CN cluster anion photodetachment properties (photoelectron spectra and angular distributions) are recorded via velocity mapped photoelectron imaging for wavelengths between 270 and 340 nm, in small energy increments. These are compared with free I(-) detachment results and reveal the presence of a sharp change in the angular distribution for the (2)P(3/2) spin orbit channel in the vicinity of the (2)P(1/2) threshold. The effect is seen at this threshold in the I(-) x H(2)O cluster anion and just below threshold for I(-) x CH(3)CN. The effect is attributed to an electronic autodetachment process, which is dependent on electronic energy transfer mediated by the electron-neutral complex produced in the excitation process. These results highlight the potential of cluster anion detachment as a probe of electron-molecule interactions and in particular the sensitivity of the angular distributions to intracluster electron transfer processes.

Anion Resonances of para-Benzoquinone Probed by Frequency-Resolved Photoelectron Imaging

“…The additional information obtained through the PADs clearly identifies the involvement of resonances; similar changes in PADs have been observed in vibrational autodetachment of anions. 53,54 In principle, PADs can be calculated using, for example, the relevant Dyson orbitals. 61,62 However, when autodetachment occurs from resonances and interference can occur with direct detachment channels, these methods become more difficult to apply and additional development on the theoretical front is required to capture changes in the PADs.…”

Vibronic coupling in the superoxide anion: The vibrational dependence of the photoelectron angular distribution

“…58,[63][64][65][66][67][68] In these cases, the change in ␤ can be explained through consideration of the dominant long range term in the potential, the centrifugal term. The free electron wave can be represented as a superposition of partial angular momentum waves for which we will use the symbol ᐉЈ ͑=ᐉ Ϯ 1͒ to allow distinction from the parent orbital angular momentum quantum number ᐉ.…”

Inter-channel effects in monosolvated atomic iodide cluster anion detachment: Correlation of the anisotropy parameter with solvent dipole moment

“…[1][2][3][4][5][6] Subject to minor perturbation from the molecular moiety, the highest lying occupied orbitals are essentially those of free I − . 2,3,5,[7][8][9][10] The cluster anion detachment spectra are similar to those of free I − and the transitions observed are most conveniently discussed according to the asymptotic atomic iodine states produced.…”