Vol 52, No 1 (2018)

A way how a general rovibronic Hamiltonian for a polyatomic molecule can be obtained using generalized coordinates and introducing a “well” for the potential function of nuclear oscillations has been shown. Eigenfunctions for individual types of motion have a very simple form, which makes it possible to analyze both low-and high-energy states of molecules without changing the solution algorithm and to form an energy matrix without changing the basis set.

The dependences of the reaction rate constant for bleaching of solutions of chlorophyll under the action of light with a wavelength of 434 and 670 on the type of solvent and additives (O₂, H₂O, HCl, and anthocyanins) have been studied.

The review discusses modern approaches to the synthesis of semiconductor colloidal quantum dots and hybrid nanosystems represented by conjugates of quantum dots and organic ligands. The mechanisms of photoinduced processes taking place in systems of this kind are considered in detail. Data on chemoand photoconvertible hybrid nanosystems are summarized.

The UV absorption spectrum of pentacene in hexane solution and the diffuse UV reflectance spectrum for its solid sample have been obtained. A spectral band due to structural features resulting from intermolecular interactions in the solid state was detected for the solid sample at the energy of 1.51 eV. The types of detected electronically excited states for pentacene have been determined, and dominating electronic configurations have been interpreted using TD B3LYP/6-31G quantum-chemical calculations. The types of pentacene occupied and unoccupied molecular orbitals involved in electronic transitions have been determined from published photoelectron spectroscopy data for pentacene with the preliminary assignment of the relevant photoionization bands using the B3LYP/6-31G calculation method.

The kinetics of radiation telomerization of tetrafluoroethylene in Freon 113 with ethanol and ammonia additives have been studied by kinetic calorimetry. Tetrafluoroethylene telomers with terminal hydroxyl and amino groups have been obtained. The molecular structure, properties, and composition of the telomers have been investigated by IR spectroscopy, thermogravimetry, and elemental analysis.

With the use of EPR, UV–VIS, and IR spectroscopy, calorimetry, and elemental analysis, it has been found that radicals are spontaneously formed under the action of molecular bromine on the methyl acrylate (MA) monomer at low temperatures; upon heating the system (225 K), these radicals initiate a polymerization reaction. This process is not efficient. The addition of bromine at the double bond of MA is the main reaction that occurs during the heating of the system (225 K).

A suspension formed as a result of ultrasonication of a mixture of graphite with N,N-dimethylformamide has been studied by ¹H NMR spectroscopy. The dependence of the width of the ¹H NMR signal on the N,N-dimethylformamide content of the suspension has been determined.

It has been shown that the precursors (long-chain amines and alkanethiols) used in liquid-phase colloidal synthesis of InP@ZnS quantum dots exert a significant influence on their spectral and luminescent properties. It has been found that dodecylamine and 1-dodecanethiol facilitate obtaining the particles with a narrow luminescence band and a low quantum yield, whereas oleylamine, 1-octanethiol, and 1,6-hexanedithiol stimulate the formation of the quantum dots with broad and intense luminescence. Conditions have been found under which the narrowing of the emission band to 46.3 nm becomes possible.

A catalyst based on plasma-chemical β-SiC and TiO₂ with a palladium content of 10 wt % has been synthesized. The dependence of the rate of the CO oxidation reaction at room temperature and low CO concentrations (less than 100 mg/m³) on the β-SiC content has been studied. It has been found that with a β-SiC content of 8 to 10 wt %, the catalyst has a maximum reaction rate, which is three times that on a catalyst based on pure TiO₂ including palladium clusters. The catalysts are promising for use in catalytic and photocatalytic air purification systems.