Yu. G. Budnikova

Chemically modified electrodes with amperometric response in enantioselective analysis

Estimation of the enantiomeric purity of chiral biologically active compounds, as well as the determination of particular optical isomers, is very important for the control of medicines, food, and biological fluids. The main approaches to the development of electrochemical enantioselective sensors with the amperometric detection of the signal are considered in this review. Examples of the use of biochemical and supramolecular receptors providing enantiomer recognition and techniques of their inclusion into the corresponding sensors are given. The main characteristics of enantioselective sensors for the determination of optically active medicines, organic acids, aminoacids, carbohydrates, alcohols, and other biologically important compounds are considered.

Electrochemistry of Organophosphorus Compounds

Progress in electrochemistry of organophosphorus compounds is rewieved. Mechanisms of oxidation and reduction reactions under the conditions of homogenous electrocatalysis and possibility of use the primary compounds for the synthesis of various organic and organoelement compounds are considered.

Electrochemical evaluation of a number of nickel complexes with P,N-heterocyclic ligands as catalysts for hydrogen oxidation/release

The efficiency of a series of nickel complexes of P,N-cyclic ligands (potential catalysts in hydrogen fuel cells) in the electrocatalytic reduction of H+ to hydrogen and the oxidation of H2 in the coordination shell/cavity of the catalyst in DMF (acetonitrile with variable nickel: ligand ratio (1: 1, 1: 2) and different counterions (X=Cl− and BF4−)) was tested, and the most favorable conditions and structures were determined. The relation between the activity of the catalysts and the values of the electrochemical gap was found.

Cyclic voltammetry of nitronyl- and iminonitroxyls detected by electron spin resonance

The combined cyclic voltammetry method (cyclic voltammetry detected by electron spin resonance, CVA-DESR CVA) was applied to study the electrochemical reactions of nitronyl- and iminonitroxyls (NN and IN) and to estimate the diffusion and absorption characteristics of their products. The ESR method yielded the hyperfine structure constants, including 13C. Even if exposed to lower temperature, all the studied NN were shown to spontaneously lose oxygen and to convert gradually into the relevant IN. For each specific NN, the combined CVA-DESR CVA experiments found the reduction potential value at which it can be virtually completely converted into the relevant IN.

Electrochemistry of nitronyl and imino nitroxides

Redox potentials of a wide group of azolyl-substituted nitronyl and imino nitroxides were determined by classic cyclic voltammetry (CV). Conclusions have been made for this group of compounds, and their peculiarities were emphasized in comparison with methyl-, phenyl-, iodo-, and cyano-substituted nitroxides.

Nickel complexes with cyclic ligands containing P and N atoms as coordination sites: novel biomimetic catalysts for hydrogen oxidation

Nickel complexes with new cyclic ligands containing phosphorus and nitrogen atoms as coordination sites are novel efficient catalysts for hydrogen oxidation. A systematic study of their electrochemical properties made it possible to classify the nickel systems in question into four groups according to the sequence of electron transfer processes in the reduction (MII-MI-M0) and to the nature of solvents and counterions. Regularities of catalytic transformations involving nickel complexes with P,N-cyclic ligands in the H2 oxidation reaction in the coordination sphere of the catalyst and a correlation between the structure of the complex and its redox properties were established. The most efficient catalysts contain phenyl and 2-pyridyl substituents at the phosphorus atom and benzyl or 2-pyridyl substituents at the nitrogen atom.

Novel High-Efficiency Ecologically Safe Electrocatalytic Techniques for Preparing Organophosphorus Compounds

Major advances and modern tendencies in electrosynthesis of organophosphorus compounds from available raw materials (mainly white phosphorus) are perused, systematized, and generalized. Potential synthetic possibilities and advantages of this intensely developing direction of elementoorganic chemistry are demonstrated.

Reactions of elemental phoshorus and phosphine with electrophiles in superbasic systems: XIX. Formation of the C-P bond with participation of elemental phosphorus under microwave assistance

Microwave irradiation facilitates phosphorylation of aryl methyl chlorides and styrene with red phosphorus in the presence of strong bases and increases the yield of the main products, tertiary phosphine oxides.

Electrochemical reduction of cobalt and nickel complexes with ligands stabilizing metal in low oxidation state

Electrochemical reduction of cobalt(ii) complexes containing π-acceptor ligands (L = bpy, Ph2Ppy) proceeds through three consecutive reversible steps: one-electron transfer to form a more stable CoIL complex, transfer of two electrons at more negative potentials to form an anionic [NiL]– complex, and reduction of the ligand to the radical anion. The stability of the cobalt complexes with different ligands decreases in the series Ph2Ppy > Ph3P > bpy.

Electrochemical synthesis of the calix[4]resorcinol nickel complexes modified with thiophosphoryl fragments

Nickel complexes of 1:1 composition with calix[4]resorcinols (L) modified with thiophosphyl fragments were synthesized. In the process of electrochemical reduction these complexes are capable of providing spherical homogeneous Ni(0)L particles with a narrow size distribution, stable both on the electrode and in the solution. The redox properties of the metal complexes were studied. The dimensions of the complexes obtained were estimated using the atomic force microscope (AFM) equipped with an electrochemical attachment.