The work examines the possibilities of generating optically inaccessible exciplexes by radiation chemistry techniques and describing them using quantum chemical methods. Two new target compounds were synthesized, and their luminescent properties were characterized. Using radiation-induced luminescence methods, the formation of exciplexes with N,N-dimethylaniline from these compounds as a result of recombination of a radical ion pair in a nonpolar solution was shown, and their luminescent characteristics were studied. Bound excited states for three possible exciplex structures and their corresponding emission spectra were calculated, and the optimal exciplex structure was shown to agree with experiment.

The anomalous vertical distribution of organic aerosol recorded on September 14, 2018, is analyzed on the basis of aircraft sounding data. It is anomalous in that, in contrast to the long-term average profile, the maximal concentration in the boundary layer during this flight was more than an order of magnitude higher than the previously measured concentrations. The contribution of aerosols of different origins to the total concentration in different tropospheric layers is estimated. The analysis of possible sources of aerosol precursors revealed quite a wide sector, on the territory of which there are boreal forests, which are sources of biogenic compounds, and objects of industrial infrastructure, which are sources of anthropogenic emissions.

Infrared multiphoton dissociation of Ge(OCH 3 ) 4 molecules by irradiation with a pulsed TEA CO 2 laser has been studied. The basic characteristics of the process have been experimentally investigated. The spectral characterization of the dissociation has been made. The product composition of the dissociation has been analyzed, and possible dissociation pathways have been proposed.

Solid propellant combustion products at a pressure of 40 atm have been studied by molecular beam mass spectrometry. A facility with a four-stage molecular beam formation system has been designed. The possibility of quantifying the composition of the combustion products is shown using as an example a composite fuel based on ammonium dinitramide and polycaprolactone.

The mechanism of formation of nanosized aerosol particles during mechanical grinding of coal from Kuzbass mines is studied. The concentration and size spectrum of aerosol particles in a mine tunnel during cutter operation were measured using an aerosol spectrometer. It is found that 90% of the particles are less than 200 nm in size. In the nanometer range, there are two peaks corresponding to average diameters of 20 and 150 nm, the first of which is due to single particles, and the second to aggregates consisting of single particles. The formation of aerosol during mechanical coal grinding in a continuous flow mill was studied. The spectrum and morphology of the particles produced in the laboratory mill are in qualitative agreement with those for the nanoaerosol formed in the mine. The influence of the coal aerosol on the combustion of gas mixtures was studied. Laboratory experiments showed that the presence of the nanoaerosol in a lean methane–air mixture significantly increased its explosibility. This was manifested in an increase in the maximum pressure and a significant increase in the pressure rise rate during explosion. The study leads to the conclusion that the nanoaerosol is formed from the organic coal components released into the gas phase during local heating of coal on the cutter teeth.

The combustion of ultrahigh molecular weight polyethylene (UHMWPE) in airflow perpendicular to the polyethylene surface (counterflow flame) was studied in detail. The burning rate of pressed samples of UHMWPE was measured. The structure of the UHMWPE–air counterflow flame was first determined by mass spectrometric sampling taking into account heavy products. The composition of the main pyrolysis products was investigated by mass spectrometry, and the composition of heavy hydrocarbons (C7—C25) in products sampled from the flame at a distance of 0.8 mm from the UHMWPE surface was analyzed by gas-liquid chromatography mass-spectrometry. The temperature and concentration profiles of eight species (N2, O2, CO2, CO, H2O, C3H6, C4H6, and C6H6) and a hypothetical species with an average molecular weight of 258.7 g/mol, which simulates more than 50 C7—C25 hydrocarbons were measured. The structure of the diffusion flame of the model mixture of decomposition products of UHMWPE in air counterflow was simulated using the OPPDIF code from the CHEMKIN II software package. The simulation results are in good agreement with experimental data on combustion of UHMWPE.

The structure of a premixed methyl decanoate/oxygen/argon flame stabilized on a flatflame burner at atmospheric pressure was studied by molecular beam mass spectrometry. The results of the experiment are compared with the results of numerical simulations using two different mechanisms of chemical reactions proposed in the literature. The main intermediate combustion products of methyl decanoate were identified by gas chromatography-mass spectrometry. Analysis of the primary stages of decomposition of methyl decanoate shows that reactions involving free radicals play a decisive role in its oxidation, which agrees well with the results of the experiments.

The thermal degradation and combustion of ultra-high-molecular-weight polyethylene (UHMWPE) doped with triphenyl phosphate (TPP) at atmospheric pressure was studied by molecular beam mass spectrometry, dynamic mass spectrometric thermal analysis, microthermocouples, thermogravimetry, gas chromatography/mass spectrometry. The kinetics of thermal degradation of pure UHMWPE and that mixed with TPP at high (≈150 K/s) and low (0.17 K/s) heating rates was investigated. The effective values of the rate constant and activation energy of the thermal degradation reaction were determined. Burning velocity and temperature profiles in UHMWPE and UHMWPE + TPP flames were measured. The composition of the combustion products in a flame zone adjacent to the burning surface of the sample was determined. TPP vapor in the flame was detected. The addition of TPP to UHMWPE was found to reduce the flammability of the polymer. It is shown that TPP acts as a fire retardant in both the condensed and gas phases.

The mechanism of reducing the flammability of ultrahigh-molecular-weight polyethylene (UHMWPE) with triphenyl phosphate (TPP) additives was investigated, using the methods of molecular-beam mass spectrometry (MBMS), differential mass spectrometric thermal analysis (DMSTA), thermocouple, thermogravimetry (TGA), and gas chromatography mass spectrometry (GC/MS). Kinetics of thermal degradation of pure UHMWPE and of that mixed with TPP was studied at high (∼150K/s) and low (0.17K/s) heating rates at atmospheric pressure. Effective values of the rate constants of the thermal degradation reaction were determined. Times of ignition delay, the limiting oxygen index, the burning rates of UHMWPE and UHMWPE+TPP and their temperature profiles in the flames were measured. The flame structure was investigated and the composition of the combustion products in the flame zone adjacent to the specimen’s combustion surface. TPP vapors in flame were found. Addition of TPP to UHMWPE was found to result in reduction of polymer flammability. TPP was shown to act as flame retardant both in the condensed and gas phases.

MARY spectroscopy is finding increasing use in the studies of transient organic radical ions and their reactions. Extending this technique to organometallic species will broaden the class of potential target compounds and can help answer important mechanistic questions in organometallic and spin chemistry. We probed this approach using a tailored Zn(hfac)2(PPO)2 complex. The synthesized complex has quantum yield and fluorescence lifetime (n-decane solution) φ ∼0.8 and τ ∼1.3ns, respectively. For this type of complex it is the first observation of MARY spectra different from those of free ligand, thus implying participation of the complex in the development of the observed signal.

The methods of probing mass spectrometry (PMS) for diagnostic of flames and for the study of kinetics and mechanism of the thermal decomposition products of energetic materials (EM) are described. Several types of instruments based on microprobe and molecular beam mass spectrometric sampling have been developed. Time of flight mass spectrometer has been used. Apparatuses for high (10 atm) and low (<1 atm) pressure have been developed for the study of combustion and decomposition of EM by PMS “in situ”. Several examples are presented to demonstrate application of PMS method for the study of EM flame structure, thermal decomposition and dynamic of ignition. Experimental data on decomposition of double base propellants ammonium dinitramide, ammonium perchlorate are presented.

Analysis of major- and trace-element compositions of water in hypersaline soda closed basin lakes of Northwestern Mongolia and Chuya basin (Gorny Altai) shows high enrichment in 238U (up to 1 mg/l). Proceeding from new data, uranium accumulation in water has been attributed to (i) location of the lakes and their watersheds in potential provinces of U-bearing rocks and (ii) uranium complexing with carbonate in presence of carbonate (bicarbonate) anions. Among the explored hypersaline soda lakes of the area, the greatest uranium resources are stored in Lake Hyargas Nuur (about 6000 ton).