Fragmentation of mercury compounds under ultraviolet light irradiation

Abstract

Ultraviolet light induced photofragmentation of mercury compounds is studied experimentally with electron energy resolved photoelectron-photoion coincidence techniques and theoretically with computational quantum chemical methods. A high resolution photoelectron spectrum using synchrotron radiation is presented. Fragmentation of the molecule is studied subsequent to ionization to the atomic-mercury-like d orbitals. State dependent fragmentation behaviour is presented and specific reactions for dissociation pathways are given. The fragmentation is found to differ distinctly in similar orbitals of different mercury compounds.

Role of ultrafast dissociation in the fragmentation of chlorinated methanes

“…The coincidence logic follows the schemes utilized earlier 17,39,[41][42][43][44][45] , where the electron detection from the HDA sends a signal to the pulsed voltage source (Directed Energy Inc. model PVX-4450) which raises the voltages in the extraction region for a specified time interval, allowing the measurement of the ion flight times. Due to the inherent di↵erences between the transmissions of the HDA and the TOFMS, there exists a high likelyhood of producing false coincidences between electrons and ions that in reality have no correlation.…”

Mechanisms of site-specific photochemistry following core-shell ionization of chemically inequivalent carbon atoms in acetaldehyde (ethanal)

“…At the other extreme, if Auger decays from different atoms produce exactly the same total energy distribution in the ions, then differences in ion behavior could still arise if the same amount of energy is deposited in different quantum states (including location) which decay in different ways. Differences in fragmentation can arise if the internal energy is in vibrational rather than electronic form, or if it is in electronic states with different charge distributions 25,26 . Fragmentation differences can also arise from spin-orbit and molecular field splittings, as previously found by the Huttula group 27 .…”