Secondary reactive species

Oxygen derived primary and secondary reactive species that are important in promoting photo-initiated (and other) AOPs are summarized schematically in Fig. 6-3. 

Ti-Cl bonds. The investigations clearly demonstrated that, in the absence of secondary reactive species (e.g., nucleophiles), isonitriles can form Lewis acid-Lewis base adducts with TiCU without undergoing a-addition. The early IR evidence for the supposed titanium imidochloride species was reassigned to the corresponding formamide which resulted from the hydration of the isonitrile in the presence of acid and adventitious water. 

Examination of equation 5 shows that if there are no chemical reactions, (R = 0), or if R is linear in and uncoupled, then a set of linear, uncoupled differential equations are formed for determining poUutant concentrations. This is the basis of transport models which may be transport only or transport with linear chemistry. Transport models are suitable for studying the effects of sources of CO and primary particulates on air quaUty, but not for studying reactive pollutants such as O, NO2, HNO, and secondary organic species. 

Olefins are the reactive species in gasoline for secondary reactions. Therefoi c. hydrogen transfer reactions indirectly reduce overcraekiiig" of the ga.soline. 

Another approach to reduction of an amide group in the presence of other groups that are more easily reduced is to convert the amide to a more reactive species. One such method is conversion of the amide to an O-alkyl derivative with a positive charge on nitrogen.102 This method has proven successful for tertiary and secondary, but not primary, amides. 

Discovery of the hydrated electron and pulse-radiolytic measurement of specific rates (giving generally different values for different reactions) necessitated consideration of multiradical diffusion models, for which the pioneering efforts were made by Kuppermann (1967) and by Schwarz (1969). In Kuppermann s model, there are seven reactive species. The four primary radicals are eh, H, H30+, and OH. Two secondary species, OH- and H202, are products of primary reactions while these themselves undergo various secondary reactions. The seventh species, the O atom was included for material balance as suggested by Allen (1964). However, since its initial yield is taken to be only 4% of the ionization yield, its involvement is not evident in the calculation. 

A kinetic study of the photolysis at low conversions by Berces and Forgeteg305 leads to the conclusion that OH is the sole reactive species formed in the primary process. At 2650 A and 2537 A, respectively, the quantum yields are 0.1 and 0.3. Secondary reactions are expected to be similar to those involved in the thermal decomposition of HN03, as discussed in the preceding section. 

Emissions of organic fragmentation products, so-called secondary emission products and reactive species from wood-based furniture coatings have been studied (Saltham-mer et al., 1999). Aliphatic aldehydes and some photoinitiator fragments have a strong... 

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