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A spectral and luminescence study was made of the efficiency of phototransformation of sulfaguanidine in water under irradiation with an OUVb-04 ultraviolet lamp (180–275 nm) and KrCl (222 nm), XeBr (282 nm), and XeCl (308 nm) excilamps. An analysis of the conversion of sulfaguanidine in water showed that the efficiency of sulfaguanidine phototransformation in water under irradiation with the XeBr excilamp is comparable to the loss under irradiation with OUVb-04, but higher than those under irradiation with the KrCl and XeCl excilamps. The maximum loss of sulfaguanidine is 99% without the introduction of additional oxidizing agents. After irradiation, several photoproducts of various nature were detected.

The spectral-luminescent properties and photolysis of phenol and some of its derivatives have been considered experimentally and by methods of quantum chemistry. It has been shown that the substitution with a methyl group ( p -cresol) and the introduction of the second benzene ring (bisphenol A) lead to a shift of absorption bands toward longer wavelengths and some changes in their intensity. The non-planar structure of p -cresol and bisphenol A promotes an increase in the efficiency of singlet-triplet conversion and a decrease in the fluorescence quantum yield. Results of calculations have established the mechanisms of photolysis of the considered molecular systems. It has been shown that the O–H bond in phenol and p -cresol is broken by the pre-dissociation mechanism. Photolysis of bisphenol A upon exposure to solar radiation proceeds by the mechanism of direct dissociation, but with a noticeable potential barrier (~12000 cm –1 ).

The stages of development of molecular photonics at Tomsk State University are presented. It was A. N. Terenin’s student, N. A. Prilezhaeva, who pioneered the Russian photochemistry and fostered the development of a Tomsk school of spectroscopists, at that time the only research team in the Asian part of Russia. In 1950, the research in the field of molecular spectroscopy and quantum chemistry of complex molecules was initiated by a Prilezhaeva’s student, V. I. Danilova, who became a TSU Professor at a later date. Fundamental problems were posed and solved, which related the spectra and the electron shell structure with the physical-chemical properties of several classes of complex organic molecules. The generalizations made by Danilova were quite valuable for the theory of molecular spectra and helped forming her own scientific school in 1970−80s.

The absorption and fluorescence spectra of charged anionic and cationic forms of bisphenol A (BPA) have been studied. The nature of electronically excited states and the photolysis of the BPA molecule have been interpreted based on results of quantum chemical calculations. The BPA spectra in an aqueous solution are compared during transition from the neutral to the ionic form. Results of calculations have shown that the small value of the fluorescence quantum yield in all examined molecular structures is determined by the high efficiency of the singlet-triplet conversion. In the anionic BPA form, a decrease in the efficiency of radiation decay channel by two orders of magnitude has been recorded caused by a change in the orbital nature of the fluorescent state compared to the neutral and cationic forms. It is shown that the probability of photolysis of the molecule under study increases due to the overlap of the absorption spectra of the anionic form in an aqueous solution under exposure to sunlight.

Theoretical calculations of excited states in the complexes of gold and silver three-atom nanoclusters with carbon quantum nanodots are performed using the M062X functional and the def2SVP {H}/def2TZVP/def2TZVPP{Ag, Au} hybrid basis set. A subsequent calculation of the excited states is performed in an approximation of the time-dependent density functional theory implemented in Gaussian09. The chromophore centers of the nanodots are modeled by heterocyclic molecules of isoquino-diazaanthracene and benzopyrano-diazanaphthalene. The clusters are attached to the nanodots using ethyl mercaptan and methoxyethane bridges of various lengths. The energy transfer channels are considered depending on the mutual arrangement of energy levels of clusters and heterocycles.

The effect of UV radiation on the efficiency of bisphenol A (BPA) phototransformation in water in the presence of polypropylene nonwoven material based on ultrafine fibers has been studied. The absorption and fluorescence spectra of the investigated substance with fibers of different properties have been obtained. After excitation with an excilamp, the main photoproduct – BPA – fluoresces in the region of ~408 nm. With an increase in the irradiation time from 0 to 10 min, the fluorescence intensity of this photoproduct increases. The absorption and fluorescence spectra of cyclohexane containing compounds desorbed from the fiber surface indicate the adsorption of the photoproduct on its surface during UV irradiation.

Effect of ultrasonic treatment on the molecular parameters of polymeric additives based on polyalkyl acrylate is investigated. The viscosity, temperature, and energy characteristics of high-wax crude oil and solutions of petroleum wax in decane and aviation fuel TS-1 in the presence of initial and ultrasonified additives are determined. Results obtained indicate that the pour point depression ability of the additives is not reduced after treatment in an ultrasonic field.

The influence of the solvent on the spectral-luminescent properties of bromcresol purple (BCP) has been studied. The spectral characteristics of BCP: half-width Δν 1/2 , Stokes shift Δν St , molar absorption coefficient ε, intrinsic excited state lifetime τ, and oscillator strength f are determined. Using the Lippert equation, the dependence of the Stokes shift of BCP on the orientational polarizability of the solvent has been constructed. An analysis of the experimental data showed that the position of the maximum of the BCP absorption band in the region of 350–480 nm correlates with the acceptor number of the solvent: with a decrease in the acceptor number, the band maximum shifts toward shorter wavelengths (water > ethanol > toluene > acetone). The lowest absorption capacity of BCP was registered in toluene. Using the Lippert–Mataga equation, the change in the dipole moment in polar protic solvents (16.2 D) upon excitation was determined, which is higher than in aprotic solvents (10.4 D) due to the formation of H-bonds.

Designs and physical aspects of photoreactors, their capabilities for a study of kinetics and mechanisms of processes proceeding under illumination with light, as well as application of photoreactors for solving various applied problem are discussed.

Sensitive and selective detection of antibiotic residues is an important issue for human health, environment, and public safety. In this work, the spectral-luminescent properties of the sulgin and methylene blue complex in water are studied. Methods of electronic absorption and fluorescence spectroscopy are used to assess the properties of the molecules that enter into specific, van der Waals, hydrophobic, and electrostatic interactions between sulgin and methylene blue. It is shown that the sulgin and methylene blue interaction constant is equal to 2.5·10 3 M –1 .