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.

The material presented in this review is devoted to scientific research carried out at one of the oldest graduating departments of ISUCT - the Department of Fine Organic Synthesis Technology. For citation: Danilova E.A., Galanin N.E., Islyaikin M.K., Maizlish V.E., Berezina G.R., Rumyantseva T.A., Suvorova Yu.V., Znoiko S.A., Kustova T.V. Achievements in the field of chemistry of macroheterocyclic compounds at the department of technology of fine organic synthesis. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 7. P. 111-119. DOI: 10.6060/ivkkt.20236607. 6826j.

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.

This report is a continuation of the authors' systematic research in the field of synthesis and study of the properties of phthalocyanines and related compounds. It is devoted to the production of substituted phthalocyanines combining substituents of various nature on the periphery, as well as their derivatives. The work describes spectral, catalytic, liquid crystal properties, thermal stability and solubility in organic solvents, in order to establish the influence of the nature of peripheral substituents, as well as the presence and nature of the metal in the coordination cavity on the physicochemical properties of the synthesized compounds. The presence of aryl substituents can impart liquid crystal, catalytic and luminescent properties of phthalocyanines and their metal complexes, and make it possible to obtain sulfonic acids and their derivatives under relatively mild conditions. Sulfonic acids occupy a special place among water-soluble phthalocyanines and have already found practical application as dyes and catalysts, and are also recommended for use in other fields of science and technology. However, information about compounds of this class combining functional groups of different nature in benzene rings, such as nitro groups, nitrogen-containing heterocyclic (especially saturated heterocycles) and oxyaryl fragments, is limited. The review analyzes and summarizes data on the synthesis of bi-functionally substituted phthalocyanines and possible areas of their practical application. Special attention is paid to the consideration of methods for obtaining initial phthalonitriles.

A simple procedure was developed for the synthesis of undescribed 4-aryloxy-5-chlorophthalonitriles and 4-arylsulfanyl-5-chlorophthalonitriles by SNAr reaction of 4,5-dichlorophthalonitrile with phenols and thiophenols in a DMF–water binary solvent. The resulting ortho-dicarbonitriles are of interest as precursors for the synthesis of phthalocyanines. The product yields ranged from 30 to 59

The interaction of the first synthesized tetra-4-chloro-tetra-5(5-methyl-2-isopropylphenoxy)phthalocyanine with pyridine, 2-methylpyridine, morpholine, piperidine, n-butylamine, tert-butylamine, diethylamine, and triethylamine in benzene was studied. The acid–base reaction is one of the rarely observed slow processes that forms kinetically stable proton transfer complexes. The structure of the complexes is described. The reactivity of tetra-4-chloro-tetra-5(5-methyl-2-isopropylphenoxy)phthalocyanine changes depending on the proton-acceptor ability and spatial structure of the nitrogen-containing base.

The interaction of cobalt(II) tetrasulfophthalocyanine (CoPc) with the ORF8 accessory protein of SARS-CoV-2 was studied by spectroscopy and calorimetry. The protein was found to shift the aggregation equilibrium in cobalt tetrasulfophthalocyanine solutions towards dimerization. Most probably, the CoPc dimer binds to ORF8 on the greater β-sheet side, thus causing fluorescence quenching. The protein affinity constant to CoPc dimer is 1.5 × 10 5 . Differential scanning calorimetry data indicate that ORF8 undergoes thermally induced denaturation in the temperature range of 38–67°C. Melting of ORF8 includes two stages, which partly overlap. The complex formation of ORF8 with CoPc leads to thermal stabilization of the protein, thus preventing the second stage of protein unfolding. Denaturation of the complex proceeds between 40 and 77°C as two temperature-separated stages. According to gel electrophoresis and immunoblotting data, visible light photoirradiation of the ORF8 complex with CoPc does not induce photooxidation of the protein. It was shown that water-soluble cobalt sulfo-substituted phthalocyanine can be considered as a potential drug inhibiting the ORF8 accessory protein.

The interaction of tetra-4-(2-methoxyphenoxy)phthalocyanine and tetra-4-(3-methoxyphenoxy)phthalocyanine with pyridine, 2-methylpyridine, morpholine, piperidine, n -butylamine, tert -butylamine, diethylamine, and triethylamine in benzene has been studied. The acid–base reaction involving n -butylamine and piperidine is an unusually slow process, leading to the formation of kinetically stable proton transfer complexes. The structure of these complexes is proposed. The change in the reactivity of tetraphenoxy-substituted phthalocyanines depending on the proton-acceptor ability and spatial structure of the nitrogen-containing base is considered. Pyridine, 2-methylpyridine, and morpholine do not form proton transfer complexes because of their weak basicity. A similar picture is observed in the case of tert -butylamine, diethylamine, and triethylamine, which have a more sterically screened nitrogen atom than that in n -butylamine and, as a result, do not react with tetraphenoxy-substituted phthalocyanines.

Complex formation processes of tetrasulfosubstituted cobalt(II) phthalocyanine with ORF3a accessory protein of SARS-CoV-2 coronavirus were studied. The interaction of ORF3a protein with SARS-CoV-2 virus with tetrasulfosubstituted cobalt(II) phthalocyanine affords a stable complex in which metallophthalocyanine exists in the monomeric form. The complex formation induces slight changes in the secondary structure of the protein by increasing the fraction of disordered fragments of the polypeptide chain. The photoirradiation of the complex of ORF3a protein of SARS-CoV-2 virus with tetrasulfosubstituted cobalt(II) phthalocyanine leads to the photooxidation of amino acid residues of the protein.

The effect of cyclic and acyclic nitrogen-containing organic bases on the formation of a zinc complex with tetra(4- tert -butyl-5-phenylsulfanyl)phthalocyanine in benzene has been studied. The acid-base interaction precedes the complex formation and plays a key role in it. The scheme is given for the formation of a zinc complex with tetra(4- tert -butyl-5-phenylsulfanyl)phthalocyanine in the nitrogen-containing base-benzene system. A relationship between the catalytic activity of the base and its proton-acceptor ability and structure is determined.

Substituted phthalonitriles containing a 2-cyclohexylphenol fragment and nitro- or 1-benzotriazolyl groups, and also phthalonitrile containing two 2-cyclohexylphenoxy groups, were synthesized using 4-bromo-5-nitro- and 4,5-dichlorophthalonitriles. Tetramerization of these precursors with zinc acetate hexahydrate resulted in the corresponding octasubstituted zinc phthalocyanines. Their spectral properties were studied.

Substituted phthalonitriles containing a 2-cyclohexylphenol fragment and nitro- or 1-benzotriazolyl groups, and also phthalonitrile containing two 2-cyclohexylphenoxy groups, were synthesized using 4-bromo-5-nitro- and 4,5-dichlorophthalonitriles. Tetramerization of these precursors with zinc acetate hexahydrate resulted in the corresponding octasubstituted zinc phthalocyanines. Their spectral properties were studied.

Transition-metal catalyzed cyanation by Rosenmund-von Braun is conventional approach to substituted phthalonitriles. However, low reaction yields, rough reaction conditions and limited access to halogenated compounds make this technique unreliable in many cases. In this work, we have established the direct C-H functionalization of 5,6-bis(4-bromophenyl)pyrazine-2,3-dicar-bonitrile(4) with benzothiazole affording the corresponding 5,6-bis(4-(benzo[d]thiazol-2-yl)phe-nyl)pyrazine-2,3-dicarbonitrile(5). The reaction pathway starts from the 4-bromoaniline, which was subjected to react with formaldoxime under Meerwein reaction conditions to give the oxime of 4-bromobenzaldehyde. Subsequent hydrolysis of oxime leads to formation of 4-bromobenzaldde-hyde. To prepare 1,2-bis(4-bromophenyl)-2-hydroxyethanone, benzoin aldehyde condensation was employed using NaCN as a catalyst. The precipitate obtained then was oxidized with CuSO4 to afford 1,2-bis(4-bromophenyl)ethane-1,2-dione. Condensation of diaminomaleodinitrile with 1,2-bis(4-bromophenyl)ethane-1,2-dione in glacial acetic acid led to the formation of 5,6-bis(4-bromo-phenyl)pyrazine-2,3-dicarbonitrile with 83% yield. Direct C-H functionalization was performed us-ing Pd/Cu-catalytic system in boiling toluene for 6 h in the presence of K2CO3 as a base and PPh3 as a ligand to obtain 5 in 73% yield. Structure of 5 was determined by Uv/Vis spectroscopy, mass spectrometry (MALDI-TOF), 1H and 13C NMR spectroscopy. According to B3LYP/cc-pVTZ cal-culations 5 has the structure of C2 symmetry. Assignment of vibrational modes of 5 was carried out via potential energy distribution analysis among internal coordinates. The complicated com-position of vibrational modes was noted. The simulated and experimental IR-spectra were satis-factorily agreed.

The authors obtain complexes CuPc(4-S-C 6 H 4 -COOH) 4 and CuPc(4-O-C 6 H 4 -COOH) 4 that are insoluble in water. The standard enthalpies of formation of these compounds are calculated using additive groups based on group systematics with Benson-type classification of fragments, allowing for the influence of the atoms’ primary environment. Thermal effects of the dissolution of crystalline phthalocyanines in aqueous solutions of various KOH concentrations at a temperature of 298.15 K were determined via direct calorimetry. Thermal effects of the stepwise dissociation of CuPc(4-S-C 6 H 4 -COOH) 4 , CuPc(4-O-C 6 H 4 -COOH) 4 are calculated using the HEAT computer program. Standard enthalpies of formation are calculated for products of the dissociation of CuPc(4-S-C 6 H 4 -COOH) 4 and CuPc(4-O-C 6 H 4 -COOH) 4 in an aqueous solution.

Complexes are obtained of tetra-4-carboxyphthalocyanines with copper and zinc that are insoluble in water. Standard enthalpies of formation of the compounds are calculated according to additive groups based on group systematics with a Benson-type classification of fragments that considers the influence of the primary environment of atoms. Thermal effects of the dissolution of crystalline tetra-4-carboxymetallo-phthalocyanines in aqueous solutions at different concentrations of KOH (0.002 to 0.02 mol/L) at 298.15 K are determined via direct calorimetry. The standard enthalpies of formation are calculated for products of the dissociation of complexes of tetra-4-carboxyphthalocyanines with copper and zinc in aqueous solutions.

A copper complex of tetra-4-(4'-methoxyphenoxy)phthalocyanine was obtained by template synthesis. Its spectral properties in solutions of chloroform, DMF, and sulfuric acid were studied. It has been established that the studied copper phthalocyanine in chloroform solution exists mainly in the monomeric form. The mesomorphism study by the method of polarization optical microscopy showed that the compound is mesogenic, exhibiting a columnar mesophase within a wide temperature range. On cooling, the compound vitrifies with preservation of the mesophase texture. Thin films of individual phthalocyaninate and its mixture with a fullerene derivative (PCBM) were obtained by spin-coating. The film thickness and surface relief were evaluated by atomic force microscopy. The spectral (absorption and fluorescence) and photophysical properties of the films have been studied. It is shown that the presence of photovoltage in individual phthalocyaninate is two times higher than in its composition with PCBM. Over time (after one year), the photovoltaic response of the film based on the individual phthalocyaninate significantly decreased, while in the film with the addition of PCBM it increased three times compared to the initial values ​​for freshly prepared samples. This behavior of photodiodes based on phthalocyanine – fullerene compositions is not typical and was observed for the first time.

A continuation is presented of a number of studies on the thermal oxidative destruction of benzotriazolyl-substituted phthalocyanines and their metal complexes, and sulfonic acids based on them. The effect the nature of the peripheral substituents and the metal complexing agent have on the thermal stability of the compounds is shown.