Reactions Proton-induced

Protons, generated indirectly by deprotonation of an intermediate during anodic oxidation of an organic substrate, are obviously produced in stoichiometric amounts. Reactions induced by these protons are typically acid-catalyzed conversions of the initial oxidation product or proton-induced reactions/deactivation of unconverted substrate. 

Fluorinated -alkenes and -cycloalkenes have a special relationship with their hydrocarbon analogues, usually exhibiting a chemistry that is complementary. For example, the fluorinated systems are frequently susceptible to nucleophilic attack, in some cases dramatically so, and therefore reactions of nucleophiles with fluorinated alkenes often reveal unique new chemistry. This chapter covers electrochemical reduction, principles governing orientation and reactivity of fluorinated alkenes towards nucleophiles, fluoride ion as a nucleophile and the mirror-image relationship of this chemistry with that of proton-induced reactions, reactions with nitrogen-, oxygen-, carbon- centred nucleophiles etc., and, finally, chemistry of some oligomers of fluorinated -alkenes and -cycloalkenes. 

The inverse relationship that exists between fluoride ion-induced reactions of fluorinated alkenes [3] and proton-induced reactions of alkenes maybe adduced from the processes described in the following sections. 

H -tetramethylbenzidine in anionic-cationic mixed micelles has been studied in detail by ESR . The photochemistry of the semi-oxidised forms of eosin Y and rose bengal have been investigated in colloidal solutions. Relevant to the fluorescence of proteins is a study of fluorescence quenching of indolic compounds by amino-acids in SOS, CTAB, and CTAC micelles O Rate constants for proton transfer of several hydroxyaromatic compounds have been measured in a variety of surfactant solutions. Photoprotolytic dissociation does not require exit of the reactant molecules from the micelles. Micellar solutions can be used to improve the fluorescence determination of 2-naphthol by inhibiting proton transfer or proton inducing reactions z2. jpe decay of the radical pair composed of diphenylphosphonyl and 2,4,6-trimethyl benzoyl radicals in SDS is affected by magnetic... 

This reaction liberated 17.3 MeV, the mass afterwards being 0.0186 AMU less than before. Beryllium, fluorine, sodium and magnesium provide nuclides which undergo proton-induced reactions. Nitrogen-14 yields carbon-11, a positron-emitter with a half-life of twenty minutes. 

Equation (3) shows that the most critical ingredients for such models are the numerous excitation functions needed. The data base for proton-induced reactions is fairly complete for most relevant noble gas nuclides as well as for most of the important radionuclides. An important exception is production from Ca, for which cross... 

Direct collisions have been independently investigated by Brown and Muir-head who have found rather higher cross sections than those obtained by the authors first mentioned. For the (w, p) reactions with 14 Mev neutrons the calculated cross sections which always contain a considerable direct interaction component, follow the general trend found by Paul and Clarke (Sect. 28) the direct component varies from a few mb in the heaviest elements to some 40 mb or more in light elements. For proton induced reactions at 18 Mev, their theoretical cross sections do not seem quite adequate to account for the direct component observed. 

Tin-117m has been in Phase II/III clinical trials for palliation of pain caused by breast and prostate cancer metastasized to bone (Atkins et al. 1993, 1995). This isotope of tin can be produced in a reactor by Sn(n,y) Sn and Sn(n,n ) Sn reactions. Alternative production routes via proton-induced reactions on Sb isotopes in an accelerator are also possible. 

Examples of Some Important Reactions Proton-Induced Reactions... 

The two proton-induced reactions are endothermic, while both of the deuteron-induced reactions are exothermic, the second strongly so. 

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