Mechanism of autoionization

Obviously, NON plays a similar role in the calculation of autoionization matrix elements. For example, see [127, 155] for ifs confribution to the understanding of fhe mechanism of autoionization. 

Y. Komninos, N. Makri, C.A. Nicolaides, Electronic structure and the mechanism of autoionization for doubly excited states, Z. Phys. D 2 (1986) 105. 

The well-documented lack of autoionization phenomena for phosgene would argue against such a mechanism, although it might be enhanced by the presence of charcoal. 

Glushkov AV, Ivanov LN, Ivanova EP (1986) Autoionization phenomena in atoms. Moscow University Press, Moscow Glushkov AV, Ivanov LN (1992) Phys Lett A 170 33 Glushkov AV (1992) JETP Lett 55 97 (2008) Relativistic quantum theory. In Quantum mechanics of atomic systems. Astroprint, Odessa... 

A qualitatively new approach to the extended fine structure in the secondary electron spectrum was proposed in [33-35]. Bearing in mind the autoionization mechanism, the authors suggested allowing for the coherent elastic scattering of electrons of both intermediate state of autoionization and the final state, i.e., the electrons detected in an experiment. In the context of this approach, the secondary electron extended fine structure results from superposition of two interference terms, both of which are determined by the local atomic environment of the ionized atom. One of them is determined by the wave number of the intermediate-state electron of autoionization, and the other by the wave number of the final-state electron detected in the experiment. 

The radiationless decay of a quasidiscrete excited state of an atom or molecule into an ion and electron of the same total energy is called autoionization. The quasidiscrete state must, of course, lie above the first ionization potential of the atom or molecule. The occurrence of autoionization may be inferred from the appearance of absorption spectra or ionization cross-section curves which exhibit line or band structure similar to that expected for transitions between discrete states. However, in the case of autoionization the lines or bands are broadened in inverse proportion to the lifetime of the autoionizing state, as required by the uncertainty principle. In the simple case of one quasidiscrete state embedded in one continuum, the line profile has a characteristic asymmetry which has been shown to be due to wave-mechanical interference between the two channels, i.e., between autoionization and direct ionization. In an extreme case the line profile may appear as a window resonance, i.e., as a minimum in the absorption cross section. 

What is the proposed mechanism of initiation of polymerization by the Lewis acid like aluminum chloride or bromide through an autoionization process ... 

Auto-ionization of dimer Lewis acids was first suggested by Korshak and Lebedev (41). Friedel-Crafts metal halide Lewis acids show varions degrees of association in hydrocarbons. Aluminum halides can form dimers and trimers (42), but TiCh was shown to be monomeric in CH2CI2 (43). The low temperature polymerization of isobutylene in n-heptane initiated by AlBrs is an example of autoionization (44). Other possible mechanisms have been postulated for direct initiation, such as formation of the carbenium ion by the interaction of a halogenated solvent with the Lewis acid, electron transfer from the monomer to the Lewis acid, and allylic hydride transfer for a summary see Reference 45. Recently, direct initiation of isobutylene polymerization by haloboration of the monomer was demonstrated (46). 

Pfleger et al. [369] have studied photoconduction in undoped poly(phenylacetylene) which they prepared by coordination polymerization of phenylacetylene using the metathesis catalyst WOCU/Pl Sn. The polymer thus obtained was predominantly in the c/5-transoidal form, as demonstrated by IR spectra, and had a molecular weight of (A/ ) 91 000. The photoconduction threshold has been detected at 410 nm, although absorption of the film extended up to 550 nm. It is suggested that the mechanism of photogeneration is intrinsic by its nature. The formation of initial charge carrier pairs occurs by an exciton autoionization process [38]. From the temperature dependence, as well as Irom the field dependence of the quantum yield, the pair separation distance was established to be ca 2.2 nm. 

An interesting approach [62,63] to this problem, the use of 02 instead of 02, further substantiated the electron attachment to vdW molecules. For the BB mechanism, the isotope effect may be expected to appear as a change in the rates of initial attachment and autoionization channels, which are caused by a decrease of the resonance energy for 2 in comparison with 02. 

This type of energy exchange in an autoionization process may correspond with the behavior of a kicked rotator in classical mechanics, which is known to exhibit chaos. It would be worthwhile to consider an autoionization process of a simple diatomic molecule in its Rydberg states to understand experimentally the essential dynamics of a quantum system, whose classical counterpart exhibits chaos. 

A relaxation process will occur when a compound state of the system with large amplitude of a sparse subsystem component evolves so that the continuum component grows with time. We then say that the dynamic component of this state s wave function decays with time. Familiar examples of such relaxation processes are the a decay of nuclei, the radiative decay of atoms, atomic and molecular autoionization processes, and molecular predissociation. In all these cases a compound state of the physical system decays into a true continuum or into a quasicontinuum, the choice of the description of the dissipative subsystem depending solely on what boundary conditions are applied at large distances from the atom or molecule. The general theory of quantum mechanics leads to the conclusion that there is a set of features common to all compound states of a wide class of systems. For example, the shapes of many resonances are nearly the same, and the rates of decay of many different kinds of metastable states are of the same functional form. 

---