Simple procedures and characterization of a series of well-defined precursors are described for preparation of a unique microenvironment in nanoreactors, reverse micelles. The Na+, K+, Rb+, Cs+, and Mg2+ surfactants were prepared using liquid-liquid ion exchange using chloride and nitrate salts. The surfactants were characterized using H-1 NMR spectroscopy and a variety of other techniques. H-1 NMR spectroscopy was found to be a sensitive probe for characterization of the size of the nanoreactor as well as its water content. H-1 NMR spectra can be used for detailed characterization of reactions in confined environments when counterion effects are likely to be important. H-1 NMR spectroscopy revealed two separate peaks corresponding to water in Mg(AOT)(2) samples; one peak arises from water coordinated to the Mg2+ ion while the other peak arises from bulk water. The two water signals arise directly from the slow exchange of the water coordinated to Mg2+ in these microemulsions with water in the water pool, and provide an opportunity to study hydration of Mg2+. This work thus extends the potential use of MAOT microemulsions for applications such as in green chemistry.