Metallosurfactants comprising copper(ii) (Cu(NO3)2) and zinc(ii) (Zn(NO3)2) nitrate complexes of 2,5-dimethyl-7-hydroxy-2,5-diazaheptadecane were found to form stable oil-in-water microemulsions - metallomicroemulsions - that could solubilise toluene in the presence of butanol. A detailed contrast-variation scattering analysis, employing both neutrons and X-rays, in conjunction with pulsed-gradient spin-echo NMR and simple phase diagram construction, demonstrated that the system formed is that of a conventional microemulsion - a core comprising toluene, separated from the aqueous phase by the surfactant and co-surfactant/co-solvent. This study further demonstrates the versatility of metallosurfactants and the similarity of their physical chemistry behaviour to that of conventional surfactants.
Paul, A., Fallis, I., Cooper, C., Wess, T., Thomas, K., Heenan, R., King, S., & Griffiths, P. (2010). A contrast variation small-angle scattering study of the microstructure of 2,5-dimethyl -7- hydroxyl -2, 5-diazaheptadecane-toluene-butanol oil-in-water metallomicroemulsions. Soft Matter, 6(11), 2552-2557. https://doi.org/10.1039/b926812j