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.

Cobalt–tetra-4-carboxyphthalocyanine complexes are synthesized. Direct calorimetry is used to determine heat effects of the dissolution of crystalline cobalt tetra-4-carboxymetallophthalocyanine in KOH aqueous solutions of various concentrations (0.002–0.02 mol/L) at 298.15 K. The standard enthalpies of formation of the compound are calculated using additive groups, based on group systematics with a Benson-type classification of fragments that considers the effect of the primary environment of atoms. Standard enthalpies of formation are calculated for products of the dissociation of tetra-4-carboxyphthalocyanine–cobalt complexes in an aqueous solution.

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.

A complex of tetra-3-carboxyphthalocyanine with copper that is insoluble in water is obtained. Thermal effects from dissolving crystalline tetra-3-carboxymetalphthalocyanine in aqueous solutions of various KOH concentrations (from 0.002 to 0.02 mol/L) at 298.15 K are determined via direct calorimetry. Measurements are made in a calorimeter using an isothermal shell with automatic recording of the temperature and electrical calibration at T = (293.15–308.15) ± 0.01 K and P = 100.5 ± 0.7 kPa. Standard enthalpies of formation of the products of dissociation of the tetra-3-carboxyphthalocyanine complex with copper in aqueous solution are calculated. Thermal effects of stepwise dissociation are calculated using the HEAT computer program.

Potentiometry and calorimetry are used to study Ce3+–glycine–ethylenediaminedisuccinic acid and La3+–glycine–ethylenediaminedisuccinic acid systems in aqueous solutions at T = 298.15 K (KNO3). The formation of a mixed-ligand complex is revealed, and the thermodynamic characteristics (ΔrH, ΔrG, ΔrS) of the complexation reaction are determined.

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.

Recently, more and more drugs that are derivatives of oligopeptides have been introduced to the pharmaceutical market. The structural elements of these compounds are amino acids and dipeptides. When stabilizing functional groups are introduced into the peptide structure, as well as through the use of special delivery systems, oligopeptide derivatives can be used as innovative med-icines. The calorimetric method was used to determine the heat of interaction of glycyl-D-phenyl-alanine with solutions of nitric acid and potassium hydroxide at 298.15K and the values of the ionic strength of the solution 0.5, 0.75 and 1.0 in the presence of KNO3. Measurements were carried out on a calorimeter with an isothermal shell and automatic recording of the temperature-time curve. The unit was equipped with a reaction vessel with a volume of 60 cm(3). Calibration was performed by current at T = (293.15-308.15) +/- 0.01 K and P = 100.5 +/- 0.7 kPa. A thermistor KMT-14 was used as a temperature sensor. The temperature of the calorimetric cell was controlled in a thermostat equipped with a PID controller with an accuracy of 0.002 K. The temperature sensor of the ther-mostat was a platinum resistance thermometer. The calorimeter was calibrated by current. The volume of the calorimetric liquid is 42.83 ml. The enthalpy of stepwise dissociation of glycyl-D-phenylalanine at zero ionic strength was found by an equation with one individual parameter. Standard thermodynamic characteristics (Delta rH degrees, Delta rG degrees, Delta rS degrees) of acid-base interaction reactions in aqueous solutions of glycyl-D-phenylalanine are calculated. The effect of the background electro-lyte concentration on the dissociation heats of glycyl-D-phenylalanine is considered. Knowledge of the thermochemical characteristics of dipeptides is necessary for understanding and subsequent modeling of the process of protein biosynthesis occurring in biological systems. Data on the ther-modynamic characteristics of dipeptide solutions are needed in various fields where these com-pounds are used: pharmacology, medicine, food and cosmetic industries, for the development, jus-tification and optimization of technological processes involving these compounds and their com-plexes with metals.

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.

The enthalpies of dissolution of crystalline glycyl-L-tyrosine in water and in aqueous potassium hydroxide at 298.15 К were determined by the direct calorimetric method. The measurements were performed on a calorimetric unit with automatic recording of the temperature–time curve. The standard enthalpies of combustion and formation of glycyl-L-tyrosine were calculated by the additive group method based on group systematics with classification of fragments of the type of Benson classification, with the effect of the initial environment for atoms included in calculation. The standard enthalpies of formation of dipeptide and the products of its dissociation in aqueous solution were calculated.

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.

3-(Pyridin-2-ylmethylene)isoindolin-1-one was synthesized by the reaction of phthalimide with 2-picoline in the presence of zinc oxide. Heating its mixture with an excess of phthalimide and zinc acetate leads to the formation of zinc 5-(2-pyridyl)tetrabenzoporphyrinate, which, upon treatment with acid, is converted to 5-(2-pyridyl)tetrabenzoporphyrin. The latter, when reacting with cobalt(II), copper(II), and iron(III) chlorides in DMF, forms the corresponding metal complexes. The composition and structure of the obtained compounds were confirmed by mass spectrometry, vibrational, 1H NMR, and electron spectroscopy. The results of quantum-chemical calculations of complexes by the DFT method are presented. It is found that the energy gap between the frontier orbitals correlates with the positions of the first bands in the electronic absorption spectra. All the synthesized tetrabenzoporphyrins exhibit catalytic activity in the electroreduction of oxygen, cobalt and copper complexes being the most active.

The thermal effects of acidic and basic dissociation of glycyl-D-phenylalanine dipeptide at a temperature of 298.15 K and ionic strengths of solution of 0.5, 0.75, and 1.0 M against the background of different supporting electrolytes were calculated from the results of direct calorimetric measurements performed on a calorimeter with an isothermal shell and automatic recording of the temperature–time curve. The influence of the nature of supporting electrolytes NaCl, NaClO 4 , NaNO 3 , KNO 3 , and LiNO 3 on the thermal effects of stepwise dissociation of the dipeptide is considered. The standard thermal effects of ionization of glycyl‑D‑phenylalanine in two steps were found by extrapolation to zero ionic strength. The standard changes in thermodynamic functions (enthalpy, entropy, and Gibbs energy) in the acidic and basic dissociation of g-lycyl-D-phenylalanine dipeptide were calculated.

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.

Определены энтальпии растворения кристаллического глицил-L-тирозина в воде и в водных растворах гидроксида калия при 298.15 К прямым калориметрическим методом. Измерения проводили на калориметрической установке с автоматической записью кривой температура–время. Величины стандартных энтальпий сгорания и образования глицил-L-тирозина были рассчитаны по аддитивно групповому методу, основанному на групповой систематике с классификацией фрагментов типа классификации Бенсона, которая учитывает влияние первоначального окружения для атомов. Рассчитаны стандартные энтальпии образования дипептида и продуктов его диссоциации в водном растворе.

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 reaction of phthalimide with zinc acetate gave a previously unknown three-unit condensation product 3-[(E,Z)-{(E,Z)-3-[(1-hydroxy-1-methyl-1H-isoindol-3-yl)methylene]isoindolin-1-ylidene}methyl]-1H-isoindol-1-one. Heating the latter with 2-methylquinoline and zinc oxide followed by treatment with sulfuric acid resulted in the synthesis of 5-(quinoline-2-yl)tetrabenzoporphyrin, which was used to synthesize heteroligand sandwich complexes of lanthanum, neodymium, gadolinium, erbium, and lutetium, containing a phthalocyanine fragment. The spectral properties and thermal stability of the sandwich complexes linearly depend on the ionic radii of the metals. The synthesized complexes are more sensitive to oxidation than lanthanide diphthalocyaninates.