Studies on solvophobic interactions and micelle formation of some surface active Cr(III) complexes in non-aqueous solvents

Micelle formation of surface active CrIII complexes of the type cis-[Cr(en)2(C12H25NH2)X]2+ (where X = F−, Cl−, Br−) have been studied in n  -alcohol and in formamide at different temperatures by conductance measurements. Standard Gibbs free energy changes (ΔGmic0), enthalpies (ΔHmic0) and entropies (ΔSmic0) of micelle formation have been determined by studying the variation of the critical micelle concentration (CMC) with temperature. Critical micelle concentrations have also been measured as a function of percentage concentration of alcohol added. It is suggested that alcohol addition leads to an increase in formamide penetration into the micellar interface that depends on the alcohol chain length. The results are discussed in terms of increased hydrophobic effect (solvophobic interaction), dielectric constant of the medium, the chain length of the alcohols and the surfactant in the solvent mixture.

Graphical abstractThe critical micelle concentration (cmc) of three kinds of metallosurfactants of the type cis-halogeno(dedocylamine)bis(ethylenediamine)chromium(III) have been studied in n-alcohol and formamide mixtures at different temperatures by the electrical conductivity method. Specific conductivity data (at 293–313 K) served for the evaluation of temperature dependent cmc values and thermodynamic parameters such as ΔGm0,ΔHm0andΔSm0.Figure optionsDownload full-size imageDownload as PowerPoint slide