<sup>1</sup>H NMR Studies of Aerosol-OT Reverse Micelles with Alkali and Magnesium Counterions: Preparation and Analysis of MAOTs

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