Benzodioxine-fused tetrapyrazinoporphyrazine complexes (BzO2)4TPyzPzM (M = Co(II), Cu(II), Zn(II), In(III)) were synthesized via two complementary routes: (i) template cyclotetramerization of benzo[1,4]dioxino[2,3-b]pyrazine-2,3dicarbonitrile, and (ii) post-functionalization of octachloro-substituted precursors Cl8TPyzPzM (M = Cu, Co) through reaction with catechol. The obtained complexes were characterized by MALDI-TOF, NMR, UV-Vis, and IR spectroscopy, and their electrochemical behavior was studied by cyclic voltammetry. Density functional theory (DFT) calculations revealed the molecular and electronic structures, highlighting the near-planar geometry of the complexes (except for the dome-shaped In(III) derivative). Electrochemical studies of graphite electrodes modified with complexes 3a-c showed that replacing chlorine atoms with dioxin fragments significantly shifts the reduction potential toward the negative region. While for the Zn complex, only the macrocyclic ligand is redox active and undergoes reduction, the redox processes associated with the central atom are observed not only for the Co(II) complex (3+/2+ and 2+/1+) couples but also for the Cu(II) complex (2+/1+) couple.

2(3),9(10),16(17),23(24)-tetrakis-(4-Tritylphenoxy)phthalocyanine and its complexes with Al(III), Ga(III) and In(III) were synthesized. The compounds were characterized by spectral analysis methods, including mass spectrometry, 1H NMR and electronic spectroscopy, and elemental analysis. The synthesized dyes show small solvatochromic effects. The aggregation behavior of phthalocyanine compounds was studied by UV-visible and fluorescence spectroscopy in dichloromethane. Based on photophysical measurements, general patterns of fluorescence quantum yields, as well as singlet oxygen quantum yields of these compounds, were revealed. The highest relative quantum yield of singlet oxygen (0.78) was shown by the indium complex. The electrochemical and electrocatalytic behavior of the complexes was studied by cyclic voltammetry. Aluminum and indium complexes are most active in the oxygen electroreduction reaction. All complexes are stable when heated to 200 degrees C in an inert atmosphere.

By reacting phthalimide with quinaldine in the presence of zinc oxide, 3-(quinolin-2-ylmethylene)isoindolin-1-one was synthesized. Heating its mixture with excess phthalimide and zinc acetate leads to the formation of zinc 5-(2-quinolyl)tetrabenzoporphyrinate, which, when treated with acid, is converted to 5-(2-quinolyl)tetrabenzoporphyrin. The latter, when interacting with cobalt(II), copper(II) and manganese(II) chlorides in DMF, forms the corresponding metal complexes. The composition and structure of the obtained compounds were confirmed by a complex of physicochemical methods of analysis. The results of quantum-chemical calculations of complexes by DFT and TD-DFT methods are presented. The first absorption bands in theoretical electronic spectra are assigned to the corresponding electronic transitions in molecules. All synthesized tetrabenzoporphyrins have catalytic activity in the electroreduction reaction of oxygen; the cobalt complex exhibits the greatest activity.

The electrochemical and electrocatalytic properties of hemihexaphyrazine and its trinuclear cobalt complex were studied by cyclic voltammetry. The possibility of detecting cationic and anionic forms of compounds in the process of polarization of electrodes in the region of potentials 0.5 divided by -1.5 V has been established. It is shown that the synthesized cobalt complex has a sufficiently high catalytic activity in the oxygen reduction reaction in an alkaline solution.

5,10,15,20-tetrakis(1'-carboxymethylpyrid-4-yl)porphyrin tetrachloride (1) and 5,10,15,20-tetrakis(1'-carboxymethylpyrid-4-yl)porphyrin tetrabromide (2) were synthesized. Water-soluble tetrapyridylporphine derivatives are salts of halides with multicharged cations with a complex aromatic structure. Thermal effects of dissolution of crystalline tetrapyridylporphins (1) and (2) in water and in aqueous solutions of KOH at 298.15 K were determined by direct calorimetric method. The integral enthalpies of dissolution were measured on a variable temperature calorimeter with an isothermal shell that we designed. The reaction part of the calorimeter and all internal parts in contact with the solution are made of titanium alloy VT-1. The volume of the calorimetric cell was similar to 60 cm(3). The stability of the thermostating system during calorimetric measurements was maintained with an accuracy of 10(-3) K. The standard enthalpies of formation of compounds were calculated using the additive group method. This method takes into account the influence of the primary environment for atoms. The values of the standard enthalpy of tetrapyridylporphine formation and its dissociation products in an aqueous solution were obtained for the first time. They are key quantities in the thermochemistry of this compound, open up the possibility of conducting rigorous thermodynamic calculations in systems with tetrapyridylporphine. The differences in thermochemistry of porphyrins (1) and (2) related to different counter -ion (chloride or bromide) opens a possibility to use solution calorimetry for distinguishing between these ions, which can be useful in some industrial applications.

Cobalt tetra- (CoPc(COOH)4) and octacarboxyphthalocyanines (CoPc(COOH)8) were obtained as starting blocks for the formation of metal-organic framework (MOFs). On their basis the corresponding MOFs containing aluminum oxide clusters of various structures as a binding component were synthesized. The activity of these materials as heterogeneous catalysts for the oxidation of 4-tert-butylpyrocatechol with atmospheric oxygen was studied. It was found that MOF based on octacarboxy cobalt phthalocyanine (CoPc(COO)8H4Al2) has greater activity compared to MOF based on tetracarboxy cobalt phthalocyanine (CoPc(COO)4Al). At the same time, the rate of the oxidation reaction of 4-tert-butylpyrocatechol catalyzed by CoPc(COO)8H4Al2 is 5.5 times higher than for CoPc(COO)4Al under equal conditions. The study of the electroreduction of molecular oxygen on graphite electrodes modified with both the cobalt phthalocyanines and MOF obtained on their basis was carried out to confirm the catalytic activity of the materials under study in the process of oxygen activation. It has been shown that CoPc(COOH)4 exhibits greater activity compared to CoPc(COOH)8 in the oxygen electroreduction processes. The resulting disagreements most likely indicate a large contribution of the MOFs structure to the catalysis processes. The morphology of the obtained materials was assessed using electron scanning microscopy. The structures of the studied compounds were optimized using quantum chemical modeling methods. Combination of the literature and obtained data made it possible to show the structures of synthesized MOFs for the first times, which are indirectly confirmed by experimental data.

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Synthesis and identification of Co(II), Ni(II), Cu(II) and Pd(II) complexes of 10,15(20)-dinitro-5-(4-nitrophenyl)-2,3,7,8,12,13,17,18-octamethylporphines was carried out for the first time. Data on the electrochemical properties of complex compounds in an aqueous-alkaline elec-trolyte were obtained by cyclic voltammetry. The values of redox potentials associated with the pro-cesses of transformation of porphyrin ligand, ion-complexing agent, the formation of cationic and anionic forms of metal complexes are determined. A general scheme of electrochemical processes of transformation of metal complexes of nitro derivatives of octamethylporphyrins is proposed, which includes a series of sequential one-electron oxidation processes-reduction of a central metal ion, an organic ligand and a nitro group. The electrocatalytic activity of compounds in the reaction of electroconduction of molecular oxygen in an aqueous-alkaline solution was evaluated. It has been established that all compounds have electrocatalytic properties and direct the process of elec-trical reduction of molecular oxygen by both two-and four-electron mechanisms. It was found that the cobalt complex of 10,15,(20)-dinitro-5-(4-nitrophenyl)-2,3,7,8,12,13,17,18-octamethylporphine has the greatest electrocatalytic activity. The influence of the scanning rate of the potential on the electrochemical parameters and reversibility of the observed processes is analyzed. The greatest for practical implementation can be considered the CoP-2 complex, where the largest shift to the pos-itive region of the half-wave potential E1/2(O2) for the process ORR and high value of the effective number of electrons (n=3.4) are observed. The influence of the scanning rate of the potential on the electrochemical parameters and reversibility of the observed processes is analyzed.

The article considers the synthesis of meso-tetrakis(1'-methyl-pyrid-4-yl)porphyrin tetratosylate and meso-tetrakis(1'-methyl-carboxymethylpyrid-4-yl)porphyrin tetrabromide. The authors qualified the porphyrin ligands in terms of the electron and 1H NMR spectroscopy. The research determines the decrease of freezing point (ΔTfr) of aqueous solutions of porphyrins, as well as a model N-methyl-pyridinium salt (1 methyl-pyridinium iodide). We used the obtained experimental values of ΔT3 to determine the isotonic coefficient. The obtained results indicate the compounds are almost completely dissociated in the indicated concentration range in dilute solutions.

The results on the electrochemical and electrocatalytic properties a number of 2,3,7,8,12,13,17,18-octamethylporphine (OMeP) nitroderivatives in an alkaline solution were obtained and analyzed for the first time. The values of redox potentials of transformation processes of organic ligand and molecular oxygen using the method of cyclic voltammetry were determined. Potentials of redox processes caused by the formation of cationic and anionic forms were determined. The identification of the electroreduction process of the nitro group in the area of ERed/Ox =-0.40 --0.6V is carried out. A general scheme of electrochemical processes of oxidation-reduction of nitro derivatives for octamethylporphyrins in an alkaline solution is proposed. The electrocatalytic activity of compounds in the oxygen reduction reaction (ORR) in an alkaline solution was evaluated. It has been established that all, with the exception of 10,15,20-trinitro-5-(4-nitrophenyl)-2,3,7,8,12,13,17,18-octamethylporphine, do not have high electrocatalytic prop-erties and direct the ORR process by a two-electron mechanism through the intermediate formation of a peroxide ion. The effect of the scanning rate of the potential on the electrochemical parameters and reversibility of the observed processes were shown.

The publication reflects the experimental substantiation and fundamental development of some important ideas of the theory of the mutual influence of functional substitution in complex molecules of macrocyclic and chelating compounds on their coordination, solvation and redox properties, as well as the formation of algorithms for searching useful functions of these compounds. Researchers of the Analytical Chemistry Department of the Ivanovo State University of Chemistry and Technology have been studying the electrochemical and thermodynamic behavior of porphyrins, complexones, amino acids, peptides and the corresponding complexes with d- and f-metal ions, their influence on coordination, solvation and catalytic processes for a number of years. The results obtained together with the literature data are discussed in the review. For citation: Bazanov M.I., Berezina N.M., Gridchin S.N., Krutova O.N., Gorboletova G.G., Bychkova S.A., Lytkin A.I., Chernyavskaya N.V., Chernikov V.V., Volkov A.V. Theoretical and experimental approaches in the study of electrochemical and thermodynamic properties of polyfunctional organic compounds in liquid-phase and heterophase systems. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 7. P. 98-110. DOI: 10.6060/ivkkt.20236607. 6839j.

In this work 5,10,15,20-tetrakis(1`-methyl-pyrid-4- and-3-yl)porphin tetratosylates and tetraiodide [H-2(1`-methyl-Py-4- and -3)(4)P](4+) (X-)(4), 5,10,15,20-tetrakis(1'-methyl-pyrid-4- and -3-yl)porphin tetratosylates cobalt [Co-tetrakis(1`-methyl-Py-4- and -3)(4)P](4+) (Ts-)(4) have been synthesized and characterized. These compounds were differed by the isomerism of the meso-substituent of the porphyrin molecule and the nature of the counterion (Ts-, I-). The data of the redox-behavior and efficiency of the use of porphyrin compounds in oxygen reduction reaction (ORR) have been obtained. The electrochemical behavior has been studied by using the cycling voltammetry method. It should be noted that two stages of the electroreduction process were observed in an argon medium for ligands. For the cobalt complexes additional processes was found. The process of the porphyrin macrocycle electroreduction in the potential region of -0.78 ... -1.36 V and the Co3+<-> Co2+, oxidation (reduction) process localized on the metal atom at E-red/ox = 0.19 V were found. The N-substitution of the pyridyl fragment of porphyrins leads to a small increase in their reducing ability, in comparison with unsubstituted tetrapyridylporphyrins [H-2(Py-4- and -3)(4)P]. The possibility of using water-soluble porphyrins in the ORR electrocatalysis has been considered. It has been shown that the nature of the metal cation has a significant effect on the electrocatalytic activity of compounds in the molecular oxygen ionization reaction of in an aqueous-alkaline media. The activity of Co-complexes was increased by similar to 50-90 mV compared with ligands and a system without a catalyst at similar to 140-160 mV.

The synthesis of meso-aryl- and beta-alkylcorroles and their metal complexes is given in the article. Electrochemical and photooxidative properties of these compounds have been studied. All synthesized corroles are characterized by the data of UV-Vis and H-1 NMR spectroscopy, and mass spectrometry.

In this paper, a series of water-soluble meso-tetrakis(1'-methyl-pyrid-4- and -3-yl)porphyrin tetratosylate and meso-tetrakis(1'-methyl-pyrid-4- and -3-yl)porphyrin tetraiodide were synthesized with high yields. All synthesized compounds were characterized by H-1 NMR, FT-IR, UV-vis spectroscopy and elemental analysis. The enthalpy changes of meso-tetrakis(1'-methyl-pyrid-4- and 3-yl)porphyrin tetratosylates dissolution in water, alcohol and phosphate buffer (pH = 6.86) were determined by the calorimetric method at 298.15 K. The effect of peripheral substituents and anion of the porphyrin molecule on the enthalpy of solvation have been studied by calorimetry and UV-vis spectroscopy. To understand more clearly the nature of changes in the meso-substituents and anion of a porphyrin molecule, we have also synthesized N-methyl-pyridinium salts (1-methyl-pyridium tosylate and 1-methyl-pyridium iodide) model. The processes of their dissolution under the same solution conditions have been investigated. The nature of the anion and isomerism of the pyridylporphyrin substituent significantly affects the thermochemical characteristics of the compounds transition into solution. In particular, porphyrin-tosylates were found to be solvated several times better than its iodide analogs. Stability to photooxidative degradation is one of the key characteristics of chromophore and characterizes the kinetic stability of a compound in solution under UV-irradiation influence in atmospheric oxygen conditions. In this regard, the stability to photooxidative destruction of porphyrinic salt derivatives has been also measured in aqueous solutions. The results indicated that N-methyl-pyridylporphyrins were stable and slowly degrade under the influence of light radiation in aqueous solutions. It follows from the observed rate constant values of porphyrins (k(obs)) photooxidative destruction that 4N-substituted porphyrins are much more stable than their 3N-substituted analogs. A similar dependence was observed for the half-flow time of the studied compounds. (C) 2019 Elsevier B.V. All rights reserved.

An influence of copper cation in the complex on structure and properties of the floating layers of 5, 10,15-triphenylcormle (Cu[(ms-Ph)(3) Cor]) at the air-water interface was studied. The structure of the layers has been determined using the method of quantitative analysis of compression isotherms. A model of stable nanostructured layers of the substance has been constructed. Copper cation in the macrocycle increases the density of two-dimensional M-nanoaggregates, while the number of molecules in such aggregates experiences 2-3-fold growth. Like the metal-free triphenylcorrole, this copper-containing compound in multilayer Langmuir-Schaeffer (LS) films with edge-on arrangement of molecules forms aggregates with strong intermolecular interactions. Such LS films may be suitable for electrocatalysis in the oxygen reduction reaction.

Методом изотермического насыщения со спектрофотометрическим контролем концентрации изучена растворимость соединений на основе 1-имино-2-фенил-1H-инден-3-амина с фрагментами 3,5-диамино-1,2,4- и 2,5-диамино-1,3,4-тиадиазолов в ДМФА и этаноле в интервале температур 298-318 К. Обсуждены закономерности растворения продуктов конденсации состава 1:2, 2:1 и 2:2 в индивидуальных растворителях. Рассчитаны термодинамические параметры растворения синтезированных соединений.

In this work acetato(3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato)iron(III) [(AcO)FeTMeTEtP] and acetato[5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato)iron(III) [(OAc)OFe(Py-3)2TMeTEtP] have been synthesized and characterized. Electrochemical properties and electrocatalytic activity of complexes in oxygen electroreduction reaction in 0.1M KOH aqueous solution were studied by the cyclic voltammetry. The comparative analysis of the effect of complex formation, as well as functional substitution in the molecule (the introduction of one or two pyridyl fragments into meso-positions of the macrocycle) on the electrochemical parameters and activity of alkyl-substituted and pyridyl-substituted porphyrins in oxygen electroreduction reaction were carried out. The research of electrochemical behavior of complexes with close structure in experimental conditions has showed that a pyridyl substituent significantly affects the studied properties. The published data and obtained in our work have showed that (AcO)FeTMeTEtP and (AcO)Fe(Py-3)2TMeTEtP are characterized by redox processes involving both the porphyrin macrocycle (L ↔ Lˉ˙, Lˉ˙ ↔ L2ˉ), and metal (Fe3+ ↔ Fe2+, Fe2+ ↔ Fe+). It should be noted that the process of electroreduction of the central metal ion (Fe3+ ↔ Fe2+) proceeds under additional introduction of oxygen into the system for the (AcO)FeTMeTEtP, (Cl)Fe(Py-3)HMeDEtP and (AcO)Fe(Py-3)2TMeTEtP. The results of investigation of the electrocatalytic activity of tetrapyrrole compounds in an aqueous-alkaline medium allows one to make a conclusion about the positive effect of complexation and the introduction of electron-donor substitutes in the porphyrin macrocycle on the electroreduction process of molecular oxygen. The electrocatalytic activity of the studied compounds in the oxygen ionization reaction were increased, according to the decrease in the half-wave potential of O2 [E1/2(O2)] in the series: H2TMeTEtP < (AcO)FeTMeTEtP < (AcO)Fe(Py-3)2TMeTEtP.Forcitation:Berezina N.M., Do Ngoc Minh, Bazanov M.I., Semeikin A.S., Maksimova A.A. Synthesis and electrochemical characteristics of Fe (III) - etio porphyrin ii and its 5,15-bis(pyrid-3-yl) derivative. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 29-34

The method of cyclic voltammetry is used for the first time to study the electrochemical behavior of cobalt phthalocyanine derivatives with fragments of benzoic acid CoPc(4-O–C 6 H 4 COOH) 4 and CoPc(4- S–C 6 H 4 COOH) 4 in an aqueous alkaline solution. Comparative analysis is carried out of the electrochemical behavior and change in the electrocatalytic activity of metal phthalocyanines in the reaction of molecular oxygen electroreduction depending on the functional substitution in the macrocycle molecule. In the case of the CoPc(4-O–C 6 H 4 COOH) 4 and CoPc(4-S–C 6 H 4 COOH) 4 compounds, central metal ion oxidation (Co 2+ → Co 3+ ) and reduction (Co 2+ → Co 1+ ) processes and also two successive one–electron stages of phthalocyanine ligand electroreduction are registered. It is shown that the studied cobalt phthalocyanine derivatives manifest electrocatalytic activity in the process of molecular oxygen electroreduction.

The dissolution of compounds based on 1-imino-2-phenyl-1H-inden-3-amine with fragments of 3,5-diamino-1,2,4- and 2,5-diamino-1,3,4-thiadiazoles in DMF and ethanol is investigated by means of isothermal saturation with spectrophotometric concentration monitoring in the temperature range of 298–318 K. Characteristics of the dissolution of the products of condensation with compositions 1 : 2, 2 : 1, and 2 : 2 in individual solvents are presented. Thermodynamic parameters of the dissolution of the synthesized compounds are calculated.