Reactivity basicity

Polyalkylene polyamines find use in a wide variety of appHcations by virtue of their unique combination of reactivity, basicity, and surface activity. With a few significant exceptions, they ate used predominantly as intermediates in the production of functional products. End-use profiles for the various ethyleneamines ate given in Table 6. 

Ellis Wilson (1991, 1992) examined cement formation between a large number of metal oxides and PVPA solutions. They concluded that setting behaviour was to be explained mainly in terms of basicity and reactivity, noting that cements were formed by reactive basic or amphoteric oxides and not by inert or acidic ones (Table 8.3). Using infrared spectroscopy they found that, with one exception, cement formation was associated with salt formation the phosphonic add band at 990 cm diminished as the phosphonate band at 1060 cm" developed. The anomalous result was that the acidic boric oxide formed a cement which, however, was soluble in water. This was the result, not of an add-base readion, but of complex formation. Infrared spectroscopy showed a shift in the P=0 band from 1160 cm" to 1130 cm", indicative of an interaction of the type... 

The low permittivity of these liquids compared with water inhibits dissociation of the acids so that cement formation demands much more reactive basic oxides. Oxides and hydroxides that are capable of cement formation are ZnO, CuO, MgO, CaO, Ca(OH)2, BaO, CdO, HgO, PbO and BiaOj (Brauer, White Moshonas, 1958 Nielsen, 1963). In practice these are confined to two calcium hydroxide and special reactive forms of zinc oxide. 

Thus, in the simultaneous liquefaction and primary catalytic hydrorefining of coal as practiced here, at the point of complete disappearance of hexane-insoluble asphaltenes very large proportions of the original coal remain as nonhydrocarbons in both the total filtered liquid product and in the distillate boiling below 1000°F. At this stage of hydrorefining, an additional input of ca. 2.2 wt % of hydrogen is required to convert all HCl-reactive, basic nonhydrocarbons to hydrocarbons and neutral nonhydrocarbons in the total filtered liquid product and about 1.7% in... 

D. J. Gale and J. F. K. Wilshire, Fibre-reactive basic dyes. I. Polymethine dyes containing the N-chloroacetyl group, J. Soc. Dyers Colour., 1974, 97-100. 

Treatment of Z-bis-thioethers RS—CH=CH—SR with alkali amides or organo-lithium result s in a smooth elimination of thiol with formation of metallated ethynyl sulfides M—C=C—SR [203]. If Z-bis(methylthio)ethene and the reactive basic system BuLi TMEDA in THF are allowed to interact at very low temperatures, no elimination occurs, but a precipitate of the lithio derivative is formed. It has a reasonable stability below — 100°C, thus permitting functionalizations... 

Because the two types of material in this category are propriety, there is relatively little information available about their composition, and what there is needs to be inferred from a variety of sources. The fact of their FDA approval as a type of resin-modified glass-ionomer is important, because it suggests that they contain both a reactive basic glass and an acid. 

Solvents. The choice of suitable solvents for anionic polymerization is determined in part by the reactivity (basicity and nucleophihcity) of initiators and propagating anionic chain ends. For styrene and diene monomers, the solvents of... 

Furans. Timm and coworkers have devised a strategy to synthesize 2,5-disubstituted furans using sulfone carbanion-mediated solid support as a traceless linker (Scheme 12.16). They demonstrated the usefulness of the highly reactive basic carbanionic species of the... 

In summary, a metal ion facilitates hydrolysis or nucleophilic displacement by some other species in essentially two ways direct polarization of the substrate and external attack, or by the generation (by ionization) of a particularly reactive (basic) reagent. One of the prime functions of a metal ion in any biological system is thus to provide a useful concentration of a potent nucleophile at a biologically acceptable pH. 

Needless to say, the electrophilic aldehyde function of 4-formylstyrene (14) must be protected prior to anionic polymerization. The most suitable protected functionality for aldehydes may be the acydic and cydic acetals that are stable to highly reactive basic reagents and nudeophiles. Indeed, a styrene para-substituted with D-gJucose (7a), whose diol functions were protected as cydic acetals, successfully underwent living anionic polymerization, as mentioned in Section 3.18.2.1. The cydic acetal-protected functionalities were suffidently stable in THF at -78 °C, but were readily deaved to quantitatively regenerate the diol functions under mild acidic hydrolysis. 

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