Ionization potential, adiabatic molecular

Even in reactions involving excited states or in reactions between two radicals, the primary interaction which determines the reactivity is thought to proceed adiabatically. The probability of nonadiabatic charge transfer also may not be ignored between a molecular specie with small ionization potential and a specie with large electron affinity, in particular in the form of free, gaseous, or nonsolvated state. In that... 

Two different values of the ionization potential / have to be considered2 3,7 (1) the adiabatic Ip, which corresponds to a transition from the zero-vibration level of the ground state of the molecule to that of the ground state of the molecular ion (2) the vertical which corresponds... 

Ab initio molecular mechanics calculations have been used to examine the electronic states of selenoxanthene 9 and selenoxanthone 10. These results were used to explain differences in the formation of bromine adducts of these compounds (see Section 7.11.6.1.2) <1998JOC8373>. Bond dissociation enthalpies and adiabatic ionization potentials of phenolic antioxidants containing selenium and tellurium have been carried out using DFT models in an attempt to design novel vitamin E analogues such as 11 <20060BC846>. 

Fig. 4.5 A comparison between the vertical and the adiabatic molecular ionization potentials. The parabolas represent the nuclear potential surfaces ofthe molecule and the molecular ion. The horizontal shifts correspond to the different equilibrium nuclear configurations of these species. Electronic energies are measured from the corresponding ground vibrational levels. (IP)v and (IP)a are the vertical and adiabatic ionization potentials, respectively.

The minimum energy required to form molecular ions by electron bombardment is known as the vertical ionization potential (IPv) and may exceed the minimum energy necessary to produce molecular ions in the ground state (the adiabatic ionization potential IPa). The stability of the molecular ion determines its abundance relative to ions that are formed by its fragmentation. The time elapsing between ionization... 

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