Electrochemical Generation of Polymorphic Structures at Charged Aqueous Interfaces. An Example of Redox Couple Methylene Blue/Leucomethylene Blue

Abstract

Leueomethylene blue (3,9-bis(dimethylamino)-phenathiazin) electrogenerated at the interface electrode/aqueous electrolyte solution forms several ordered structures which depend strongly on the potential and charge of the electrode surface and type of anions present at the interface. Interconversion between the structures, provoked by potential steps (1 mV – IV) is characterized by fast phase transitions corresponding to progressive two-dymensional nucleaiton and growth.

Kinetics and mechanism of the fast charge transfer process (10³<k<10⁴ s⁻¹) through the ordered multilayer films at mercury, gold and platinum electrodes are presented.