Charles R. Leidner

Quinone molecular films derived from aminoquinones

Abstract A series of aminonaphtho- and aminoanthraquinones have been employed to prepare adherent, electroactive, and electrochromic polymeric quinone films on electrode surfaces. Films of thicknesses ranging from an equivalent of one to several thousand monomolecular layers can be prepared electrochemically by the oxidation of acetonitrile solutions of the monomers. These aminoquinone films exhibit the expected quinone/semiquinone and semiquinone/quinone dianion couples at negative potentials, as well as the polyaniline-like couples at more positive potentials in non-aqueous solvents. Spectroelectrochemical experiments using SnO 2 /glass electrodes document the expected electrochromic behavior of the polymer films in CH 3 CN. Preliminary chronoamperometric experiments in CH 3 CN indicate rapid electron transport rates for the quinone/semiquinone couples. The aminonaphthoquinone film shows complete electroactivity in acidic aqueous solutions. The quinone/hydroquinone couple (2 e − 2 H + ) shifts negatively, with increasing pH; however, the voltammetry becomes more distorted at higher pH. Voltammetric and chronoamperometric results reveal that charge transport is more rapid for the reduction than for the oxidation in aqueous acid.

Synthesis and properties of a plasmalogen quinone

Abstract A novel phospholipid quinone bearing hexadecyl ether chains has been synthesized and employed in the preparation of redox-active, quinone-functionalized liposomes.

Lipophile exchange membranes as electroactive assemblies on electrode surfaces

Abstract Electroactive assemblies on glassy carbon electrodes have been prepared by incorporation of lipophilic quinones into lipophile exchange membranes composed of poly(Nmethyl-4-vinylpyridinium dihexadecylphosphate) (PVPMe+ DHP−). These assemblies exhibit stable electrochemical responses when immersed in aqueous solutions. The electrochemical response of quinone - PVPMe+ DHP− layers prepared from short and long chain 2-alkylaminoanthraquinones depends on the nature of the quinone lipophile, mol% of quinone within the layer, PVPMe+ : DHP− ratio, and pH of the contacting aqueous solution. Superior performance is observed in basic solutions with low mol% quinone.