Negative charge preservation

Temporary hair dye products usually are formulated at a neutral or slightly acidic pH. Besides the dyes, the formulations may contain a small amount of a quaternary amine to neutralize the negative charge on the dyes, a fragrance, a small amount of a solvent or surfactant to solubilize the fragrance, and a preservative (Table 6). 

Notice that preserving the cation-anion ratio ensures that the soiution is eiectricaiiy neutrai overaii. The totai positive charge carried by one moie of equais the totai negative charge carried by two moies of Cl. ... 

In order to preserve electrical neutrality, the solution gains a small negative charge (see Fig. 6.3). This particular process is a reduction process. 

Five-membered heterocycles (C). That structural motif was determined in few cases only (34 and 35). It has one endo- and one exocyclic N—N bond, and only one of the negatively charged nitrogen atoms is in a bridging position. The rings adopt a twist conformation. The structure seems to be preserved in solution, and no dynamic processes were determined by NMR spectroscopy. 

In this case the starting materials had an overall negative charge and this is preserved as the oxyanion in the product. The charge disappears from the hydroxide ion because it is now sharing a pair of electrons with what was the carbonyl carbon atom and a charge appears on what was the carbonyl oxygen atom because it now has both of the electrons in the old ft bond. 

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