Synthesis, CMC Determination, and Outer Sphere Electron Transfer Reaction of the Surfactant–Complex Ion, cis-[Co(en)2(4CNP)(DA)]3+ with [Fe(CN)6]4– in Micelles, β-cyclodextrin, and Liposome (Dipalmidoylphosphotidylcholine) Vesicles

Abstract

The surfactant cobalt(iii) complex, cis-[Co(en)2(4CNP)(DA)](ClO4)3, en = ethylenediamine, 4CNP = 4-cyanopyridine, DA = dodecylamine, was synthesized and characterized by physico-chemical and spectroscopic methods. The critical micelle concentration value of this complex was obtained from the conductivity measurements at different temperatures to evaluate, ΔGm0, ΔHm0, and ΔSm0. The kinetics of outer sphere electron transfer reaction of this complex with Fe(CN)64– ion in micelles, β-cyclodextrin as well as in liposome vesicles media were studied. The rate constant increases with increase in the concentration of micelles but decreases in presence of β-cyclodextrin, which is a good structure breaker of micelles. In liposome vesicles media the rate constant is different at below and above phase transition temperature. The results have been explained based on the hydrophobic effect, the presence of pyridine ligand containing 4-cyano substituent and the reactants with opposite charge.

Kinetics and Thermodynamics of Formation and Electron‐Transfer Reactions of Surfactant Cobalt(III) Complexes Containing Polypyridyl Ligands with Fe(CN)64−in Microheterogeneous Environment

“…In β‐CD media, β‐cyclodextrin retarded the rate of the reaction by the inclusion of long‐chain amine of the complexes into the cavity of β‐cyclodextrin. On comparing the previous reports on electron‐transfer reactions of surfactant complexes, the rate constant of the present complexes is higher because the amphiphilicity of the complex can modify the kinetics of its redox reaction.…”

“…The second‐order rate constant of double chain surfactant cobalt(III) complexes ( 1–3) is higher than that of previous reported single‐chain surfactant cobalt(III) complexes . In these micelles, the reactants are encountered in a small volume of the Stern layer of the micelles leading to enhancement of concentration of reactants at the microlevel leading to higher rate and lower activation energy.…”

Microheterogeneous mediated electron transfer reaction (ETR) of surfactant cobalt(III) complexes by Fe2+: Effect of pyridine substituent as co ligand

“…The surfactant cobalt(III) complexes, 1, 2 and 3 used as oxidants were prepared as reported earlier (Nagaraj and Arunachalam, 2013a, 2013b, 2013c. A stock solution of Fe 2+ was prepared by dissolving pure iron powder in slight excess of perchloric acid.…”

“…Micelle forming properties and electron transfer reactions of many of these types of surfactant metal complexes have been studied in our laboratories for a long-time (Nagaraj and Arunachalam, 2013a, 2013b, 2013c. In previous papers (Nagaraj and Arunachalam, 2013a, 2013b, 2013c, we have reported the influence of temperature on the behavior of some surfactant cobalt(III) complexes in micelles and b-cyclodextrin solution.…”

“…In previous papers (Nagaraj and Arunachalam, 2013a, 2013b, 2013c, we have reported the influence of temperature on the behavior of some surfactant cobalt(III) complexes in micelles and b-cyclodextrin solution. In continuation of our works on the same surfactant cobalt(III) complexes in microheterogeneous (liposome vesicles (DPPC) and ionic liquids ((BMIM)Br) media.…”