Collisional electron transfer

The thermochemistry of sulfur radicals in the gas phase has been reviewed. Methylsulfonyl radicals and cations have been produced by femtosecond collisional electron transfer in the gas phase. When formed by vertical collisional electron transfer from cation CH3SO2+, radical CH3S02 dissociates to CH3 and SO2. Radical CH30S0 exists as a mixture of syn (19a) and anti (19b) isomers which are stable when formed by collisional electron transfer to the corresponding cation. Dissociation of both isomers of CH30S0 formed CH3 and SO2 via isomerization to methylsulfonyl radical. An ab initio study on the formation of the thiyl peroxyl radical has also been reported. Julolidylthiyl radicals (20) were formed by femtosecond photo-dissociation of the corresponding disulfide and have been observed... 

Keywords. Neutralization-reionization mass spectrometry, Ion chemistry, Collisional electron transfer, Franck-Condon effects, Reactive intermediates... 

Fig. 3. Schematic energy diagram for electronic states formed by collisional electron transfer...

Excited electronic states have also been considered to explain NR dissociations of heterocyclic radicals in which low-energy losses of hydrogen atoms compete with high energy ring-cleavage dissociations. The latter reactions were interpreted as starting from excited electronic states of the radicals [27,28]. Formation of excited electronic states upon collisional electron transfer has also been studied with smaller molecular systems, e.g. CHn [45], 02 [46], and H3 [47,48],... 

A different experimental approach to NRMS is embodied in the tandem quadrupole acceleration-deceleration instrument that uses quadrupole mass filters for mass selection and analysis of low-energy (70-80 eV) ions whereas collisional electron transfer is carried out after ion acceleration to 4-8 keV kinetic energies (Fig. 5) [10, 50]. The reionized products are decelerated back to 70-80 eV for mass analysis. The quadrupole instrument achieves unit mass resolution of NR products and it is versatile enough to allow variable-time and photoexcitation experiments described briefly below. Coupling with soft ionization methods... 

The next important phenomena that the result of supramolecular effect are the concentration and proximity effects concerning the components of analytical reaction, even through they are considerably different in hydrophobicity, charge of the species, complexing or collisional type of interaction. The concentration and proximity effects determine the equilibrium of analytical reaction, the efficiencies of intramolecular or intermolecular electronic energy or electron transfer and as a result the sensitivity of analytical reactions. 

Energy transfer occurring in nonreactive neutral-neutral collisions is a very active field of investigation.230 Important contributions to the understanding of collisional energy-transfer processes have also resulted from various studies of nonreactive ion-neutral collisions. The modes of energy transfer that have been investigated for the latter interactions include vibrational to relative translational (V-T), vibrational to vibrational (V-V), translational to vibrational (T-V), translational to rotational (T-R), vibrational to rotational (V-R), translational to electronic (T-E), and electronic to translational (E-T). 

COLLISIONAL ENERGY-TRANSFER SPECTROSCOPY WITH LASER-EXCITED ATOMS IN CROSSED ATOM BEAMS A NEW METHOD FOR INVESTIGATING THE QUENCHING OF ELECTRONICALLY EXCITED ATOMS BY MOLECULES... 

Collisional Energy-transfer Spectroscopy with Laser-excited Atoms in Crossed Atom Beams A New Method for Investigating the Quenching of Electronically Excited Atoms by Molecules... 

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