Structuring Redox Polymers Poly[M(Schiff)] (M = Ni, Pd; Schiff = Schiff Bases) on a Molecular Level: Methods and Results of an Investigation

Abstract

This work is devoted to a consideration of methods of electrochemical synthesis of redox polymers poly[M(Schiff)], where "M" is Ni, or Pd and "Schiff" stands for a four-dentate Schiff base, with a controlled distribution of structural elements (stacks) over the electrode's surface for the optimization of the transport of charge-compensating ions, which is the stage that determines the charge transfer rate in the system under consideration. It is shown that the structuring of these polymers on a molecular level by means of a purposeful selection of the composition of the initial compounds and the conditions of synthesis-the potential of formation and the nature of the solvent and supporting electrolyte-makes it possible to a considerable extent accelerate the charge transfer process in the polymers and improve stability of their electrochemical characteristics.

Electrocatalytic Properties of Ni(II) Schiff Base Complex Polymer Films

“…Electrodes modified with salen type ligand complexes are obtained by anodic electropolymerization, carried out in a solution of the complex in a solvent with poor coordinating properties [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Conductivity of polymer films is ensured by charge delocalization through polymer chains formed by phenyl – phenyl [ 26 , 27 , 28 , 29 , 30 , 31 ] or π-stacking interactions [ 32 , 33 ]. The mechanism of electropolymerization is still under discussion.…”

“…The mechanism of electropolymerization is still under discussion. It can be based on a ligand [ 26 , 27 , 28 , 29 , 30 , 31 ], a central metal ion [ 32 , 33 ] or both a ligand and central ion [ 34 ].…”

Electrocatalytic Study of the Thin Metallopolymer Film of [2,2′‐{1,2‐Ethanediylbis[Nitrilo(1E)‐1‐Ethyl‐1‐Ylidene]}Diphenolate]‐Nickel(II) for Ethanol Electrooxidation

“…The formation mechanism of the polymeric film on the conductor surface can be ascribed to the interaction between d‐ orbitals of the metal centers with π‐orbitals of aromatic rings of adjacent monomers, which enables easier electronic communication between the nickel centers in the conjugated backbone. The polymer organization is pre‐established by insertion of the counter‐ion from the supporting electrolyte as charge balance into the positively charged structures that form the metallopolymer columns. The coverage of the metallopolymer on the GC was confirmed by the linear dependence of the anodic and cathodic peak currents with the potential scan rates (10 to 200 mVs −1 ).…”

Modification of supercapacitor electrodes with polymer metallocomplexes: Methods and results

“…According to our data, the developed HSC prototype was only slightly worse than the DSC prototype: when the power donated during discharg ing increased by an order of magnitude (from 0.025 to 0.25 W), the energy stored by HSC decreased by only 20%. This is the consequence of the ability of poly [M(Schiff)] complexes to provide high charge trans port rates on passing from oxidized to neutral state and vice versa [4,5].…”

“…The compounds were stacks formed by donor-acceptor interactions between the ligand of one polymer fragment and the metal center of another. The poly [M(Schiff)] polymers can undergo a revers ible electrochemical oxidation and reduction in a wide range of potentials (to 3 V) and are characterized by high charge transfer rate [4,5], unique thermal stabil ity (to 370°С), and high specific values of stored energy (~330 J/g of polymer). Due to these properties, the materials can be used in energy storing systems such as supercapacitors.…”