Hydrazinium salts quaternary

In the field of surface-active cations, ion-pair chromatography is predominantly applied to the analysis of quaternary ammonium compounds, pyridine, pyrrolidine, and piperidine quaternisates, and for sulfoniiun, phosphonium, ammoniiun, and hydrazinium salts. 

Isoindoles from cyclic quaternary hydrazinium salts s. 27, 449 <-... 

Aziridines from ethylene derivatives via quaternary hydrazinium salts... 

Quaternary hydrazinium salts from ethylene derivatives... 

Apart from the product classes discussed above, which include the most important types of cleavable surfactants, several more or less exotic examples of surfactants with limited half-life have been reported. For instance, isethi-onate esters with very high degrees of alkali lability have been developed. These products, made by esterification of an alkylpolyoxyethylene carboxylic acid with the sodium salt of isethionic acid, have been claimed to be partially cleaved when applied to the skin [68]. Cleavable quaternary hydrazinium surfactants have been explored as amphiphiles containing a bond which splits very easily. The surfactants are cleaved by nitrous acid under extremely mild conditions [69]. Ozone cleavable surfactants have been developed as examples of environmentally benign amphiphiles. These surfactants, which contain unsaturated bonds, break down easily during ozonization of water, which is a water purification process of growing importance. Both normal surfactants [70] and geminis [71] have been synthesized and tested in ozonolysis. The latter surfactants contained unsaturation either in the hydrophobic tails or in the linker unit. 

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