Accession Number : ADA131726

Title :   Mechanisms and Kinetics of Diphthalocyanine Electrode Processes.

Descriptive Note : Final rept. 1 May 80-31 Mar 83,


Personal Author(s) : Nicholson,M M ; Weismuller,T P ; Pizzarello,F A

PDF Url : ADA131726

Report Date : Jul 1983

Pagination or Media Count : 31

Abstract : Redox processes of lutetium diphthalocyanine were investigated by chemical, electrochemical, and optical spectroscopic methods. Oxidized films of the dye slowly reverted from the red to the green state on standing in moist air. The rate of this color change depended on the nature of the anion that had been incorporated during the oxidation. The feasibility of faster chemical switching and of color cycling by indirect coulometry was demonstrated. Slow-scan cyclic voltammetry of film specimens on tin oxide electrodes provided evidence of incipient phase transitions in blue reduced forms of the dye. The current-voltage curves could be interpreted on the basis of a model in which the electron-transfer processes were assumed to be much faster than the phase transitions. Finally, the role of oxygen in the dye system was elucidated through discovery of a reversible oxygen reaction with lutetium diphthalocyanine in dimethylformamide solution. This information explains some apparent discrepancies in the chemistry of rare-earth diphtalocyanines and provides an important link in the formulation of a unified redox reaction scheme. (Author)

Descriptors :   *Electrodes, *Electrochemistry, *Phthalocyanines, *Reaction kinetics, Rare earth compounds, Oxidation reduction reactions, Optical properties, Spectroscopy, Chemical shifts, Coulometers, Films, Cyclic Tests, Voltammetry

Subject Categories : Electrical and Electronic Equipment
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE