Organometallic amphiphiles: novel mechanisms for redox chemical control of aggregation behavior

Abstract

Many natural and synthetic organic amphiphiles have been discovered, prepared, and/or characterized. Aggregation behavior has been studied for many of these monomers. Very few of these many amphiphiles are organometallic compounds and almost nothing is known about this novel group of amphiphiles. Under appropriate circumstances, aggregation of certain organometallic amphiphile monomers can be controlled by use of redox switching. Compounds which are not amphiphilic can be made so and amphiphilic compounds can be deprived of this property by appropriate alterations in the metal ion's oxidation state. Redox-switched aggregation-deaggregation behavior is described for bis(hexadecycloxy)-1,10-phenanthrolinium perchlorate ( 2), its nickel complex ( 3), [CH 3(CH 2) 15NH 2] 2Ag +AcO − ( 4) and bis(hexadecylamine)copper dichloride ( 5), chloride acetate ( 6) and diacetate ( 7), all of the general formula: [CH 3(CH 2) 15NH 2] 2Cu 2+X 2 2. Two completely new switching mechanisms are disclosed for the first time which involve electron transfer from dilute aqueous sugar solutions or from solid zinc metal which are effective in collapsing [CH 3(CH 2) 15NH 2] 2Cu 2+X 2 2− vesicles.