New Nickel(II) Complexes with Tetradentate Schiff Bases Containing Electron-Acceptor Substituents

Russian Journal of General Chemistry - Complexes [Ni(3-NO2SalEn)] and [Ni(3-NO2SaltmEn)] were synthesized and identified, and polymers based on them were obtained. It was found with the help of...     

Synthesis and study of catalysts of electrochemical oxygen reduction reaction based on polymer complexes of nickel and cobalt with Schiff bases

The article presents the results of studies of new nanosize catalysts of electrochemical oxygen reduction reaction (ORR) obtained using the method of thermal decomposition of polymer complexes of nickel and cobalt with tetradentate (N₂O₂) Schiff bases. The catalysts are characterized using the methods of thermogravimetry, electrochemical quartz microgravimetry, scanning electron microscopy with X-ray microanalysis, XPS. The ORR process on electrodes modified by the above catalysts was studied using the voltammetry and rotating disk electrode techniques. The obtained catalysts manifested high specific activity per initial polymer mass (more than 600 mA/mg).     

Supramolecular Associates of Nickel(II) Complexes with Nitro-Substituted Tetradentate Schiff Bases

Crystal structures of N,N'-ethylenebis(3-nitrosalicylideneiminato)nickel(II) [Ni(3-NO2SalEn)] and N,N'-(2,3-dimethylbutane-2,3-diyl)bis(3-nitrosalicylideneiminato)nickel(II) [Ni(3-NO2SaltmEn)] were determined by single crystal X-ray diffraction analysis. The [Ni(3-NO2SalEn)] complex forms supramolecular associates in the crystal phase, which affects its solubility, thermogravimetric, and spectral characteristics.     

Synthesis and Structure of Cobalt(III) Complex with Cyanomethylene and N,N′-Ethylenebis(3-methylsalicylideneiminate)

Russian Journal of General Chemistry - The new complex [CoIII(3-CH3Salen)(CH2CN)]·CH3CN was synthesized and its crystal structure was determined by the X-ray diffraction analysis. The...     

Oxygen Electroreduction Catalysts Based on Polymer Complexes of Nickel with Schiff Bases

In energy-storage systems such as fuel cells and metal-air batteries, the main current-forming process is the reaction of oxygen electroreduction (OER). A simple method is proposed for synthesizing OER catalysts based on polymer complexes of transition metals (nickel, palladium) with Schiff bases prepared by electrochemical polymerization of starting monomers. The OER catalysts are prepared by thermolysis of polymers in inert atmosphere. Their properties are characterized by the methods of cyclic voltammetry with the use of a rotating disk electrode. The surface state (the catalyst film density, the size and composition of particles) is controlled by scanning electron microscopy with X-ray microanalysis. The electrode demonstrates the high catalytic activity in the oxygen electroreduction reaction in alkaline solutions (higher than 750 mA/mg of the initial polymer mass).     

New functional materials based on conductive polymer—metal complexes modified with metallic nanoelectrodes

Russian Chemical Bulletin - The results of the synthesis and investigation of new composite functional materials are presented. The new materials are conductive polymer layers of the cobalt,...     

Photogalvanic and photovoltaic effects in systems based on metal complexes of Schiff bases

The nature of the processes that occur when electrodes modified with complexes [M(Schiff)] (M = Ni, Pd, Pt; Schiff denotes four-dentate Schiff base ligands) are irradiated with visible light for the potential use of these electrodes in photoelectrochemical energy conversion devices is considered. The factors responsible for shifts in the electrode potential upon photoexcitation, i.e., the nature of the metal site, the nature of the substituents in the sensitizer, and the oxygen concentration are discussed. Tentative mechanisms of the photovoltaic effects observed for conventional and semiconductor electrodes modified with [M(Schiff)] complexes are determined.     

Modification of supercapacitor electrodes with polymer metallocomplexes: Methods and results

A procedure for electrochemical modification of carbon materials with high specific surface was developed. The materials were modified with polymeric nickel complexes with Schiff bases. The prototype of a hybrid double-layer Faraday supercapacitor with a positive carbon electrode modified with a polymeric complex was studied. Modification of this type doubled the energy stored by the hybrid capacitor compared with the similar double-layer capacitor.     

In situ electrochemical microbalance studies of polymerization and redox processes in polymeric complexes of transition metals with Schiff bases

The mechanism and kinetics of polymerization of [M(Schiff)] complexes (M = Ni, Pd, Cu; Schiff is tetradentate N₂O₂ Schiff bases) and also the regularities of redox processes involving poly-[M(Schiff)] polymers are studied by electrochemical quartz crystal microbalance method. The number of electrons involved in the reversible oxidation-reduction of each polymer fragment is calculated and the composition of species that take part in the charge transport at the polymer oxidation-reduction is elucidated.