Nickel- N,N’ – bis (salicylidene)-1,3-propanediamine (Ni- Salpn ) film-modified electrodes. Influence of electrodeposition conditions and of electrode material on electrochemical behaviour in aqueous solution

Abstract

Influence of electrode material EQCM UV-vis and Raman spectroscopy a b s t r a c t Modified electrodes based on films of Schiff base complexes are excellent candidates for sensing applications. The influence of the electrode material, glassy carbon, platinum, gold or indium tin oxide, on the electrodeposition of nickel-N,N'-bis(salicylidene)-1,3-propanediamine (Ni-Salpn) films in 1,2-dichloroethane (DCE) was investigated, and their electrochemical behaviour was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The effect of the electrodeposition potential and electrodeposition time on the electrochemical behaviour of Ni-Salpn was examined using glassy carbon as substrate. The film growth process was investigated using the electrochemical quartz crystal microbalance and UV-vis absorption spectroscopy and structural differences between the Ni-Salpn complex and the Ni-Salpn film were examined by micro-Raman spectroscopy. The results demonstrate that the electrodeposition mechanism is independent of the electrode material, but that the nature of the substrate material influences the rate of film growth, the electrochemical behaviour and the stability of the film-modified electrodes in aqueous solution. Counteranion insertion during oxidation can break the bonds between the complexes in the stacked Ni-Salpn film structure and cause both mass loss and blockage of the redox metal centre activity, but these effects are small in thin films.

Understanding the Charge Storage Mechanism and Electrochemical Performance on the Poly[Ni(salen)]-modified Electrode Electropolymerized with Different Sweep Rate

“…During the charge transport process, a possibility is the nickel oxides formation, which resulted Electrochemistry, 85(8), 461-468 (2017) in the loss of redox ability. 17 Moreover, redox process may be impeded by the ion diffusion from bulk electrolyte to the inner of salen-film. The result indicates a transition from a filmy layer status (I p linearly increases with v) to semi-infinite diffusion control (I p increases with v 1/2 ) for the thicker polymer films.…”

Aryl‐Aryl Coupling of Salicylic Aldehydes through Oxidative CH‐activation in Nickel Salen Derivatives

“…Intending to make the synthetic route most affordable, in the described electrochemical aryl coupling procedure we have used “reagent grade” acetonitrile, which is not claimed to be anhydrous. It is known that traces of water have severe impact on the electroactivity of metal‐Salen based polymers . However, in this study the polymer is used just as an intermediate product, therefore it electrochemical properties are out of the scope of the research.…”

Unusual Ni⋯Ni interaction in Ni(ii) complexes as potential inhibitors for the development of new anti-SARS-CoV-2 Omicron drugs

“…Some researchers postulate the formation of intermolecular metal-phenyl π-stacks or metal-metal bonds in the starting monomers ("stacked polymer"). 19 The stackedpolymer model is based on the observation of anisotropic conductivity in polymeric nickel salen-complexes. 20 There are several metal-based strategies for the fight against COVID-19, and its Omicron variants have been explored in the literature.…”

“…Some researchers postulate the formation of intermolecular metal–phenyl π-stacks or metal–metal bonds in the starting monomers (“stacked polymer”). 19 The stacked-polymer model is based on the observation of anisotropic conductivity in polymeric nickel salen-complexes. 20…”