Synthesis and Reactivity of a Surfactant Ferrocene. Environmental Effects on Oxidation of Ferrocene in Organized Media

This paper reports on the synthesis of a surfactant ferrocene, 16‐ferrocenylhexadecanoic acid, ( 1 ), which can readily be incorporated into monolayer films and assemblies, micelles and vesicles. The reactivity of this ferrocene towards potential oxidants and complexing agents has been investigated in the different media under a variety of conditions. In the monolayer assemblies ( 1 ) was readily oxidized by I 2 but inert towards exposure to aqueous Ag + , aqueous TCNE or TCNO vapor. The inertness of ( 1 ) under the latter conditions suggests the chromophore is oriented in a highly hydrophobic site. In contrast, ( 1 ) is readily oxidized by I 2 and Fe 3+ in lecithin vesicles and anionic SDS micelles. In cationic CTAB micelles iodine is reactive as an oxidant but Fe 3+ is not, presumably due to charge effects. The results suggest that the ferrocene moiety in ( 1 ) is not rigidly oriented in the hydrophobic core of the vesicles or micelles but spends sufficient time near the hydrophobic interface to be oxidized by polar reagents.