Electron-exchange reactions defined

Actually, the separation of donor and acceptor contributions to the electronic matrix element is not likely to be simple. One might define the resonance exchange reactions,... 

However, if the combustion reaction is not complete, one has to introduce the Faradaic efficiency eP = nexp/nth, defined as the ratio between the number of electrons exp effectively exchanged in the overall reaction and the theoretical numbers of electrons nth for a complete oxidation of the fuel (to H20 and CO2). eP = 1 for hydrogen oxidation, whereas eF = 4/6 = 0.67 for methanol oxidation stopping at the formic acid stage (four electrons exchanged instead of six electrons for complete oxidation to C02). This reduces further the overall energy efficiency, which becomes... 

In this article, we present applications of CASVB to chemical reactions the unimolecular dissociation reaction of formaldehyde, H2CO — H2+CO [5], and a series of hydrogen exchange reactions, H2+X — H+HX (X-F, Cl, Br, and I). The method in this article is based on the occupation numbers of VB structures that are defined by the weights of the spin-paired functions in the CASVB functions, so that we could obtain a quantitative description of the nature of electronic structures and chemical bonds even during reactions. 

The study of cocatalysis in cationic polymerizations is extremely complicated by the fact that Lewis acids can participate in a variety of ill defined reactions (91). Satchell (91, 92) regards the hydrogen exchange reaction between Bronsted acids and aromatics catalyzed by Lewis acids as a prototype for Friedel-Crafts catalysis. He postulates that cocatalytic efficiency is determined by the stability of the complex anion B -f HX + SnCl4 - BH SnCl4Xe. A simple enhancement of conventional acidity by B + HX -> BH Xe as proposed by Plesch (93) and Russel (94) is considered to be unimportant. The stability of the complex and its catalytic activity are determined by the electron density... 

The chemiluminescent reaction of diphenoyl peroxide [26] with easily oxidized, aromatic hydrocarbons, reported by Koo and Schuster (1977b, 1978), was the first well-defined example of an electron-exchange chemiluminescent reaction of an organic peroxide. Its study led to the postulation of chemically initiated electron-exchange luminescence as a generalized mechanism for efficient chemical light formation (Schuster, 1979 Schuster et al., 1979). 

Usanovic acid-base theory — A general theory of acids and bases taking into consideration electron exchange processes (redox reactions) was proposed in 1939 by Usanovic. His definition is a symmetrical one and includes all concepts discussed above, i.e., an acid is defined as a substance which is able to liberate protons or other cations (cation donator) or to take up anions or electrons (anion acceptor, electron acceptor). A base is defined as a substance which is able to release anions or electrons (anion donator, electron donator) or to take up protons or other cations (cation acceptor). According to that theory, all chemical reactions (excluding reactions between radicals resulting in covalent bindings) can be considered as acid-base reactions. 

Electrochemical equivalent — Amount of a chemical substance deposited, dissolved, or transformed in an electrochemical redox reaction with exchange of one unit of electric charge. In the SI unit system the electrochemical-equivalent unit is in kgC-1, or alternatively, in molC-1. It means that in a n-electron redox reaction (Ox + ne Red) the electrochemical equivalent is equal to the molar mass M of the reacting compound divided by n times the - Faraday constant (M/nF). In some sources the electrochemical equivalent is defined as the mass of the substance transformed by electric charge corresponding to the Faraday constant. 

In this contribution we discuss how electrochemical measurements and IR spectroscopy may be used to rank electron donating abilities of boratabenzene ligands. We also try to correlate these measurements with the exchange reactions of well-defined zwitterionic compounds of the type [Cp fCjllsB—R)ZrMe][MeB(C6Fs)3]. 

Here an electron is transferred from a donor molecule D to an acceptor molecule A. In addition it is useful to define self-exchange reactions of the components as given by... 

Many electron transfer reactions of inorganic radicals conform to the outer-sphere model and hence can be modeled with the Marcus theory of electron transfer.71 This model relies, in part, on the concept of self-exchange reactions, and the inference that self-exchange reactions can be defined for radicals. For many years, it was simply... 

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