Electrode modification with a poly(Ni^II‐tetramethyldibenzotetraaza[14]annulene) film. Electrochemical behavior and redox catalysis in alkaline solutions. I

Abstract

The voltammetric behavior in alkaline solution of a nickel-based chemically modified electrode (Ni-CME) prepared by oxidative electropolymerization of a nickel-tetraazaannulene complex (Ni"L) was investigated. After electrochemical deposition of the (Ni"L), film in dichloromethane on a conducting substrate, the modified electrode was continuously cycled in alkaline solution until a steady voltammetric profile was obtained. Although upon electrochemical treatment in basic solutions the nickel-nitrogen tetracoordination of the (NiI'L), film is probably lost, the nickel species remain entrapped inside the polymeric skeleton and exhibit stable redox behavior resembling that of the nickel hydroxide ele'ctrode. This makes it possible to prepare very thin films of nickel-based modified electrodes. In cyclic voltammetry experiments the Ni-CME exhibits a pH dependence of the peak potentials typical of the a-Ni (OH)2/y-NiOOH redox process, and a separation between anodic and cathodic peak potentials of 64mV at pH 13.2 and 10 mV s-'. The redox catalysis at Ni-CMEs of representative compounds that are not easily electrooxidized, such as choline, cadaverine, y-amino butyric acid (GABA), benzyl alcohol, and glycine, is demonstrated. The good stability of these nickel-based modified electrodes makes them attractive in analytical applications.

Electrochemical Capacitive Behaviour of Multiwalled Carbon Nanotubes Modified with Electropolymeric Films of Nickel Tetraaminophthalocyanine

“…As the cycling continues, the peaks grow steadily until they reach a steady state where no further growth is observed. This is typical of cyclic voltammograms recorded for electroformed nickel macrocyclic-based films in alkaline solution and shows that the film has been formed as a result of the anodic polymerization of the macrocyclic complex [32]. The CV shows one redox couple with formal potential (E 1/2 ) at ca.0.42 V vs. Ag j AgCl, which is assigned to the N(II)/Ni(III) redox process of the nickel centre of the NiTAPc.…”

Electrocatalytic Properties of Electropolymerized Ni(II)curcumin Complex

“…Moreover, the procedure for their preparation is usually simple and the properties of the resulting coating can be controlled carefully. Electropolymerization procedure was used successfully for modifying electrode surfaces with Ni(II) cyclam and other similar Ni(II) tetraazamacrocyclic complexes [4] or Ni(II) tetramethyldibezotetraaza (14)anulene [5], and the resulting films showed high catalytic activity toward electrooxidation of alcohols and/or other À OH and À NH 2 containing compounds, respectively.…”

Novel Ni(II) Mixed Ligand Complex Modified Electrode: Catalytic Effect on Anodic Oxidation of Phenol

“…Indeed, the formation of Ni(II) 3 Ni(III) are reported in several systems viz. Ni(II)-peptide [26] and Ni(II)-porphyrin [27]. The studies thus provide information regarding electroactivity, redox system and stability of the complex.…”

“…The Ni(II) 3 Ni(III) conversion at low potential may probably serve as a fast electrontransfer mediator for the oxidation of phenol as evident by the enhanced oxidation of phenol at the complex modified graphite electrode. It has been already reported that electrochemically formed nickel porphyrin coated electrodes exhibit good electrocatalytic activity for the oxidation of carbohydrates, benzyl alcohol [27], methanol, ethanol, propanol and hydrazine etc. [28,29].…”