The partitioning of primary alcohols into the aggregates of gemini amphiphiles determined from diffusion NMR experiments.

The partition constants (-values) of primary alcohols in solutions containing aggregates of symmetric gemini surfactants of the family ,'-dimethyl, -dialkyl-,-alkanediammonium dibromide (m-s-m = symmetric gemini surfactants) have been computed from the measured values of their diffusion coefficients obtained from NMR-diffusion experiments. From the -values, both mole-fraction and concentration-based partition coefficients and Gibbs energies of transfer for the alcohols from the bulk DO phase to the gemini aggregate phase have been calculated. As expected, the Gibbs energy of transfer decreased linearly with an increase in the alcohol carbon length for each of the primary alcohol/gemini amphiphile series studied.

Improved Green Synthesis and Crystal Structures of Symmetrical Cationic Gemini Surfactants.

Gemini surfactants are composed of two hydrocarbon tails with corresponding polar headgroups, linked via a covalent spacer. The synthesis of these surfactants is a very active area of research due to their application as catalysts and other applied areas of study. The modification of green microwave techniques developed in our research on ionic liquids has resulted in the significant improvement of the synthesis of '-bis(dimethylalkyl)-α,ω-alkanediammonium dibromide (m-s-m type) symmetrical gemini surfactants.