Aggregation of bis(N-octanoylaminocarboxylato) magnesium(II) complexes in water/organic solvents

作者:Er Hua; Izutani Junko; Gerille Naren; Iida Masayasu*
来源:Colloids and Surfaces A: Physicochemical and Engineering Aspects , 2011, 392(1): 213-219.
DOI:10.1016/j.colsurfa.2011.09.058

摘要

The aggregation of magnesium(II) complex surfactants of bis(N-octanoylalaninato) (= Mg(oct-ala)(2)) and bis(N-octanoylphenylalaninato) (= Mg(oct-phe)(2)) in water/organic solvent (= chloroform, 1-hexanol, and cyclohexanol) mixtures and the effect of water on the aggregation behavior were studied using electric conductivity, NMR spectroscopy, and viscosity. Because of the moderate hydrophile-lipophile balance, Mg(oct-ala)(2) and Mg(oct-phe)(2) form aggregates in hydrophobic organic solvents by encapsulating water which assists the dissolution and aggregation of the metal complexes. A change in the structure from a reverse micelle to an onset of bicontinuous microemulsion in water/1-hexanol or water/cyclohexanol mixed solvent was detected with an increase in the water content. The strong ionic interaction between the magnesium ion and the ligand was reflected in the characteristic aggregation behavior of the magnesium surfactants. Correlation times of the hydration water bound to the metal-complex aggregates in wet chloroform system were determined by the measurements of (2)H(2)O longitudinal relaxation times.