This effect is caused by the ability of coumarin salts to thermally react with monomers at elevated temperatures. However, at elevated temperatures, their activity increases dramatically. They exhibit excellent photoinitiating activity toward monomers such as vinyl ethers, epoxides, oxetanes, and glycidyl ethers at room temperature. Due to the intense ICT absorption band, new photoinitiators are active at 365 nm, 405 nm, and 415 nm. They differ in the strength of the push–pull effect, which determines all properties of such compounds. Five new coumarin-based iodonium salts exhibit two patterns of D–π-A structure – longer and shorter. The influence of the arrangement of electron-donating substituents in the coumarin chromophore on their photophysical properties and photoinitiating activity is analysed. The peaks occur in the region below 300 cm –1 depending on the method used to prepare the initial povidone–iodine complex.In this article, we described a new group of cationic photoinitiators. The water solubility of iodine increases in the presence of iodide ions, such as potassium iodide, as a result of the formation of water-soluble triiodide ions ( \(\)) cause strong peaks in the combination scattering spectrum. Iodine readily dissolves in ethanol or diethyl ester to produce brown solutions and in chloroform and benzene to produce purple solutions. An aqueous solution of iodine is yellowish-brown in color. Iodine is the least reactive halogen and has a relatively low water solubility (0.33 g/L, 1–2 mM at 25☌). When chilled, iodine vapors crystallize without passing through a liquid stage. When heated at an atmospheric pressure, iodine sublimes to form a purple vapor. Iodine exists as slightly lustrous dark-purple crystals at room temperature. The chemist Courtois was the first to isolate molecular iodine in 1811, and Gay-Lussac named it as a new chemical element. Iodine is a chemical element (I) that occurs in the form of iodide salts in nature and is found in marine algae, fish, mollusks, and, to a lower extent, marine water. The review considers the main chemical properties of iodine, the mechanisms of iodine–polymer complexation, and the applications of iodophors. Iodophors are stable upon long-term storage, and their side effects are extremely rare. The broad range of iodophor applications makes it possible to design various iodine–polymer formulations, such as solutions, ointments, foaming creams, films, mucoadhesive tablets, etc. Cells were not degraded completely, but pores arose in the cell wall to cause leakage of cell components. For example, the effects of the iodophor polyvinylpyrrolidone (PVP)–iodine were studied in bacterial cells by electron microscopy and biochemical methods and were found to include rapid separation of the cytoplasm, nucleotide coagulation, and loss of enzymatic activities. Membranes and the cytoplasm are thus quickly destroyed in cells exposed to iodine. Iodine is additionally capable of binding with fatty acids at C–C bonds and certain nucleotides (adenine, cytosine, and guanine), thus altering the structures of nucleic acids and the entire cell membrane in bacteria. The changes affect the structure and functions of microbial cells. ![]() Iodine binds with proteins to cause their denaturation via several mechanisms, e.g., by oxidizing the SH groups in cysteine and methionine residues and preventing hydrogen bonding between the amino groups of arginines and histidines and the phenol groups of tyrosines. While antibiotics are localized in a particular site, iodine simultaneously affects all structures of a microbial cell. Iodine possesses antimicrobial and antiseptic properties. Complexation with polymeric carriers increases the solubility of molecular iodine, facilitates its prolonged release, and decreases the steady-state concentration of free iodine. Natural and synthetic water-soluble polymers and nonionic surfactants are broadly used as solubilizing agents. Iodophors are chemical complexes that contain a mixture of molecular iodine, iodide ions, and a solubilizing agent. In the early 1950s, a “conquest” of iodine started with investigating its complexation with certain polymers to yield compounds of a new class, which are known as iodophors. However, its use was limited by several undesirable factors, such as irritation, an increase in sensitivity, staining of biological and artificial surfaces, a low solubility in water, and a high vapor pressure. Iodine has long been used as an antiseptic to prevent and treat a broad range of infections.
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