Selection principle

The principles and practice of corrosion inhibition have been described in terms of the factors affecting inhibitor performance and selection (principles) and the more important practical situations in which inhibitors are used (practice). For the latter a brief account is given of the nature of the system, the reasons for inhibitor application and the types of inhibitor in use. 

Radical additions lo double bonds are, in general, highly exothermic processes and rates increase with increasing temperature. The rcgiospccificity of addition to double bonds and the relative reactivity of various olefins towards radicals are also temperature dependent. Typically, specificity decreases with increasing temperature (the Reactivity-Selectivity Principle applies). However, a number of exceptions to this general rule have been reported. 8 63... 

Reaction scheme, defined, 9 Reactions back, 26 branching, 189 chain, 181-182, 187-189 competition, 105. 106 concurrent, 58-64 consecutive, 70, 130 diffusion-controlled, 199-202 elementary, 2, 4, 5, 12, 55 exchange, kinetics of, 55-58, 176 induced, 102 opposing, 49-55 oscillating, 190-192 parallel, 58-64, 129 product-catalyzed, 36-37 reversible, 46-55 termination, 182 trapping, 2, 102, 126 Reactivity, 112 Reactivity pattern, 106 Reactivity-selectivity principle, 238 Relaxation kinetics, 52, 257 -260 Relaxation time, 257 Reorganization energy, 241 Reversible reactions, 46-55 concentration-jump technique for, 52-55... 

This Lewis acid ability of increasing both the reaction rate and the selectivity of the cycloaddition is surprising, since in other catalyzed reactions an increase in the reaction rate is accompanied by a decreased selectivity according to the reactivity selectivity principle. This apparently contradictory behavior of the Lewis acids has been explained theoretically [6,7]. 

R. J. Madix, Selected principles in surface reactivity reaction kinetics on extended surfaces and the effects of reaction modifiers on surface reactivity, in The Chemical Physics of Solid Surfaces and Heterogeneous Catalysis, Vol. 4, ed. D. A. King and D. P. Woodruff, Elsevier, Amsterdam, 1982, 1. 

Table 7.1 Some selected principles of hyphenated methods...

Rinsing, for electroplating, 9 786-787 in ion exchange, 24 412 Rio Declaration, 24 162-163, 185, 188 selected principles from, 24 194-196 Riot control agents, 5 814, 823-824 Ripeners, in photographic crystal growth, 29 182... 

In other words, under these restrictive conditions, outer sphere electron-transfer reactions obeying the Marcus-Hush model are typical examples where the Hammond-Leffler postulate and the reactivity-selectivity principle (see, for example, Pross, 1977, and references cited therein, for the definition of these notions) are expected to apply. 

Nogueira, R., Lubda, D., Leitner, A., Bicker, W, Maier, N.M., Lammerhofer, M., and Lindner, W, Silica-based monohthic columns with mixed-mode reversed-phase/weak anion-exchange selectivity principle for high-performance liquid chromatography, J. Sep. ScL, 29, 966, 2006. 

MSN. 103.1. Prigogine and C. George, The second law as a selection principle The microscopic theory of dissipative processes in quantum systems, Proc. Natl. Acad. Sci. USA 80,4590-4594 (1983). 

In the perspective of drug discovery it should be well acknowledged upfront that the primary role of chemogenomics resides in my opinion to provide starting points for future drug optimization projects which continue to rely on the classical medicinal chemistry and in vivo pharmacology-based design and selection principles. 

The theory underlying this effect depends critically on two selection principles (1) the nuclear spin dependence of intersystem crossing in a radical pair, and (2)... 

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