Synthesis, photophysical and electrochemical characterization of phthalocyanine containing triarypyride groups

Today, compounds such as phthalocyanines, crown ethers, cryptands, rotaxanes, calixarenes, podands, tetrapyrrole derivatives such as porphyrins, polyethers, porphyrazines, polythioethers, polyamines can be counted in the macrocyclic compounds with large ring structures. Complex compounds containing at least nine members and three heteroatoms, which have wide usage areas thanks to these properties, are called macrocyclic compounds. Coordination order has an important place in living things for the continuation of life. Publications are used in many fields and are widely available on it. It is a complex that contains the prosthetic group of hemin in hemoglobin, which is the protein responsible for transporting oxygen in daily blood, or a pyrrole pass in chlorophyll, which is the active pigment substance in photosynthesis in plants, and its content contains ions. The macrocyclic group compounds of coordination chemistry are used in many industrial applications; It plays an active role in a rich area such as pigment and catalysis oxidation, macrocyclization reactions, polymerization technology, as reagents, lacquer coating, product enrichment, waterproof and fireproof material production, drug production, extraction of metals, use in biological systems important for living things. Macrocyclic compounds having nine or more members (including all heteroatoms); They are cyclic organic compounds containing three or more donor (bonding, that is, electron donor) atoms that are shared or bonded to a skeleton. Studies on macrocyclic structures were not common in the beginning, except for porphyrins, corrins and phthalocyanine complex structures, and the reason why phthalocyanines were given importance compared to other macrocycles is that they have a similar structure to naturally occurring macrostructures such as heme, cytochrome or chlorophyll, or have an important potential as a pigment and dyestuff. Although phthalocyanine molecules have structurally similar structures to porphyrins, they are not found naturally in nature, such as chlorophyll A, hemoglobin and vitamin B12. The difference between them is due to the fact that the metal atoms (transition metals such as zinc, copper, nickel) and the side chains that the phthalocyanine molecules contain are different. Especially in recent years, interest has increased in macrocyclic compounds, in which phthalocyanine structures are included and related, thanks to the diversity of their properties and usage areas, and various studies are carried out in this context. Pyridine, chemical formula C5H5N, is a basic heterocyclic organic compound containing a single heteroaromatic ring, which comes from the replacement of a CH group in the benzene ring with a nitrogen atom. Pyridine has a conjugated system with six π electrons delocalized on the heterocyclic ring, exactly as benzene has. The molecule is planar in nature and follows Hückel criteria for aromaticity. Pyridines also play an important role in the life sciences. The pyridine nucleus and its derivatives obtained by alkylation are included in many natural products such as vitamins, alkaloids and coenzymes, as well as in many drugs, insect ( It is found in pharmaceutical and agricultural chemicals used for herbicide) and fungi (fungicide) destruction. Because of their π-stacking abilities, some pyridines are used in supramolecular chemistry. The pyridine ring system, especially 2,4,6-triarylpyridine, is of great interest in the synthesis of pharmacologically and biologically active materials due to its unique position in medicinal chemistry. For example, these structures show different activities such as anesthetic, antimalarial, antioxidant, anticonvulsant, antiepileptic, fungicidal antibacterial and antiparasitic properties. Therefore, the preparation of pyridine derivatives has attracted great interest in the past and in recent years. A wide variety of catalysts and synthetic methods have been investigated for the synthesis of 2,4,6-triaryl pyridine derivatives. Phthalocyanines were first obtained in 1907 as a dark blue insoluble compound as a by-product during the synthesis of orthocyanobenzamide from phthalimide and acetic acid. However, this phthalocyanine compound, which was found by chance, did not attract much attention at that time. Phthalocyanines, which are macro-sized and ring-bearing coordination compounds, were discovered by chance and later developed by researchers, and their use in electrocatalysis and photodynamic therapy, especially in the paint and pigment industry, has become quite widespread over time. Phthalocyanines, which are connected to each other with aza bridges at the 1,3 position, are generally synthesized from phthalonitrile and its derivatives (phthalimide, phthalic acid, etc.) or substituted products with metal-free and metal salts at high temperatures. Phthalocyanines are aromatic macrocyclic structures containing 16 metals, 8 carbons and 8 nitrogens, with planar 18-π electrons, similar to tetraazaporphyrins, containing four pyrrole rings attached to dense blue or green side chains depending on the metals they contain. Having a planar and 18-π electron structure determines their aromatic and electronic properties and application areas. The name phthalocyanine (Pc) was first used in 1933 to describe organic compounds consisting of metal-free and metallic phthalocyanines and their varieties. The most important properties of metal phthalocyanines are their high electron transfer ability. The relationship between the phthalocyanine ring and the central atom affected by the π electrons in the conjugated state of the phthalocyanine ring underlies this important feature, and the type and number of substituted groups form the basis of the electron transfer feature. Despite the high electron capabilities of phthalocyanines, metallized phthalocyanine structures are limited in electrochemical applications due to their low solubility in commonly used organic solvents. Their intense absorption in their electronic spectra enables phthalocyanines to exhibit extraordinary optical and electrical behaviors, to be thermally and chemically resistant to environmental factors and to gain resistance to strong acids and strong bases. The two hydrogen atoms at the center of the molecule can replace more than 70 transition metals in the periodic table to form phthalocyanines. In this way, metallized phthalocyanine complexes with new properties can be obtained. Since phthalocyanines can be substituted with various functional groups and obtained compounds with different structural properties, apart from metal-free phthalocyanines, there are types such as metallized phthalocyanines, substaphthalocyanines, asymmetric phthalocyanines, and these compact derivatives have also offered different application areas such as sensors. The fact that phthalocyanines are hydrophobic derivatives that prevent the interaction of the large or long chain molecule with water by the attachment of various substituents to the environmental positions of the phthalocyanine compound increases the solubility of most phthalocyanines in organic solvents. Phthalocyanines are soluble in methanol (MeOH), ethanol (EtOH), tetrahydrofuran (THF), dimethylformamide (DMF), dimethylsulfoxide (DMSO), chlornaphthalene, quinoline. Industrially, it was produced for the first time in 1935 and put on the market. In this structure, the metallized phthalocyanine was separated from the ring plane and attached to the inner part of the cavity in the macro ring plane. This bonding creates intermolecular forces between the phthalocyanine rings. This contributes to the regulation of the hydrophobic and hydrophilic regions of the structure obtained in polar organic solvents. In this way, the metal complex separated from the ring plane settles in the gap in the macro ring, excluding the polar part of the molecule, while entrapping the hydrophobic region inside, increasing its solubility. This structural improvement has contributed to the widening of the practical use of phthalocyanines. Phthalocyanines have been the subject of research and various applications in many fields such as organic and inorganic chemistry, materials science, electrochemistry, biochemistry and environmental sciences. Phthalocyanines are synthetic compounds that have a wide range of uses due to their optical properties and stability. Both metallic and non-metallic phthalocyanines are used in many different fields. Phthalocyanines are used in laser printers, dye-sensitized solar cells (DSSC), chemical and gas sensors, fuel cells as catalysts and electrocatalysts, liquid crystal color display applications, photovoltaic cell elements, information technologies, photoconductor elements in photocopiers, electrochromic display devices. In addition, substituted and unsubstituted phthalocyanines are used in printing inks as dyes and pigments, in the coloring of plastic and metal surfaces, as well as in many areas such as photodynamic therapy of cancer (PDT) and other medical applications. Spectral and electrochemical methods used to investigate the spectral properties and characterization of phthalocyanines; It can be counted as Infrared Spectroscopy, 1H-NMR Spectroscopy, UV/Vis Spectroscopy, Mass (MS) Spectroscopy, Voltammetry. The properties of phthalocyanines such as redox properties, electrochemical activities and electron transfer properties can be investigated by electrochemical methods. Photophysical properties of synthesized copper and zinc phthalocyanine compounds are examined. Among them, techniques such as UV-Vis spectroscopy, fluorescence spectroscopy can be used to determine the absorption spectrum, fluorescence efficiency, emission spectrum and fluorescence lifetime of the compound. Aggregation means that molecules come together to form larger structures. Phthalocyanines are compounds that show aggregation tendency. These molecules can come together through intermolecular interactions to form various aggregates or supramolecular structures. Aggregation can affect the photophysical and optical properties of phthalocyanines and plays an important role in their applications. Optical and electrochemical properties of the synthesized compounds were examined in detail within the scope of the thesis study, and two new phthalocyanine compounds (ZnPc and CuPc) containing Zn(II) and Cu(II) symmetrically substituted pyridine were synthesized. It was determined that ZnPc and CuPc in THF were not aggregated. Thus, it has been revealed that the compounds in THF media can be easily used in applications such as photodynamic therapy. It was determined by UV-vis absorption studies that both compounds were H-type or J-type aggregates in solvents such as DCM and DMSO. Accordingly, it was determined that the aforementioned aggregate phthalocyanines could prevent protein aggregation, which is seen in foods and causes various diseases. After purification by appropriate methods, the structural characterization of the compounds was performed by FT-IR, 1H-NMR, UV-Vis, MALDI-TOF-MS and 13C-NMR techniques. With the results obtained, the possibilities of use in different electrochemical techniques have been determined. Finally, the electrochemical properties of ZnPc and CuPc were investigated by the alternating voltammetry technique. The synthesized compounds showed properties to convert solar energy into electrical energy in solar cells. The obtained results showed that the synthesized compounds can be easily used in areas such as photodynamic therapy, food and photovoltaic. Demonstrating, expanding and commercializing the use of phthalocyanine compounds, which are easy to synthesize and economical compared to their counterparts, in existing or potential applications is of great importance in terms of our country's independence in areas with high added value.