Optical methods for ecological mapping of urban areas

The results of the study of spectral characteristics of tree crops of Samara city as a method for measuring air pollutant concentrations. Even-age plantings of European white birch at ten points of Samara near main motorways were chosen as objects of study. It was shown that the ratio K of the light backscattering intensities at wavelengths of 750 and 550 nm is sensitive to pollutants and insensitive to measurement conditions. The relation between the coefficient K and the leaf chlorophyll concentration and their dependence on the total concentration of anthropogenic substances characteristic of internal-combustion engine exhausts (CO, NO₂, SO₂) were experimentally determined. The carbon oxide concentration has the strongest effect on the coefficient K. This makes it possible to apply the described method tested by the example of Samara city to ecological mapping of city territories.     

Isotherm of α-tocopherol adsorption on acid-activated clinoptilolite tuff

Adsorption of α-tocopherol from ethanol solution on clinoptilolite tuff activated with 4.0 M HCl is studied. α-Tocopherol adsorption isotherm is analyzed using the Langmuir, Freundlich, and Redlich-Peterson adsorption theories. The adsorption of α-tocopherol from dilute solutions on this sorbent is ascertained to be described by the Langmuir model.     

Characterization and Spatial Matching of Laser Diode Beams

It is shown that the type of lateral waveguide of a laser diode cannot be determined uniquely based on just the measured magnitude of astigmatism. For a unique determination, the K-factor of Petermann, which characterizes the wavefront curvature at the laser output facet, must be measured as well. In order to determine the type of lateral waveguide, a setup for measuring astigmatic distances in the range 0–200 m with an error of ±2 m and a K-factor with an error of 20% was developed. Operational features of the setup were analyzed, and a technique that allows one to minimize the effect of beam ellipticity on the measurement results was found. Using the technique, the optimization of spatial matching of a laser diode with a ring interferometer of the butterfly type was accomplished. For transformation of the astigmatic elliptical beam into the axially symmetric mode of the interferometer, we have used an optical system that consists of two cylindrical and one spherical lenses. The algorithm for designing the matching system was developed, and the 85% injection of radiation of a AlGaAs laser diode into the principal mode of a ring interferometer was experimentally demonstrated.     

The effect of porphyrin supramolecular structure on singlet oxygen photogeneration

This work is to show that activity of porphyrins in singlet oxygen generation (SOG) is determined not only by their molecular structure but also by supramolecular structure of porphyrin containing systems. This is demonstrated by results of studies of SOG in the gas phase by vacuum deposited tetraphenylporphyrin (TPP) layers under photoexcitation conditions. The structure of the layers was studied by atomic force microscopy (AFM), TEM in diffraction regime (TED) and by the flicker-noise spectroscopy (FNS) method. It was shown that substrates affect the deposited layers structure only at earlier stages of the layer formation. AFM and TED data, together with FNS quantitative parameters of TPP layers, show directly that the chemical activity of solid-phase systems can be determined not only by their chemical nature but also by their supramolecular structure.     

Side Reactions in the Liquid-Phase Cyclohexanone Ammoximation

Influence of metal ions on hydrogen peroxide decomposition on the liquid-phase ammoximation of cyclohexanone was studied in homogeneous and heterogeneous (over titanium silicalite) conditions. The latter reaction is accompanied by side reactions, which deactivate the catalyst. Deactivation behavior is discussed.     

Mass spectrometric study of the overheated vapor over nickel(II), Copper(II), and Zinc(II) <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Ethylenebis(salicylaldiminato) complexes

A mass spectrometric study of the overheated vapor over the nickel(II), copper(II), and zinc(II) N,N′-ethylenebis(salicylaldiminato) complexes between 300 and 865°C has been carried out. Throughout this temperature range, the overheated vapor over all of the complexes contains no ions heavier than the molecular ion [MO₂N₂C₁₆H₁₄]⁺. At ∼600°C, Cu(salen) and Zn(salen) interact with the structural material of the double-chamber two-temperature effusion cell (Kh18N10T steel). The complexes are thermally very stable. The fragmentation pattern of the chelates under electron-impact ionization is metal-dependent.     

Mass spectrometric study of the overheated vapor over Ni(II), Cu(II), and Zn(II) N,N′-ethylenebis(acetylacetoniminato) complexes

A mass spectrometric study of the overheated vapor over the complexes Ni(acacen), Cu(acacen), and Zn(acacen) (H₂acacen = N,N′-ethylenebis(acetylacetonimine)) has been carried out in the temperature range of 180–760°C. Irrespective of the degree of overheating, the vapor phases over all of these compounds contain no ions heavier than the molecular ion [MO₂N₂C₁₂H₁₈]⁺. The existence of molecular ions in the overheated vapor in the double-chamber two-temperature effusion cell is evidence of the high thermal stability of the complexes. The onset temperature of the thermal decomposition of Ni(acacen), Cu(acacen), and Zn(acacen) is 690, 610, and 560°C, respectively. The way of fragmentation of the chelates under electron impact ionization depends on the nature of the metal.     

Complexation of strontium with triisopropyl ester of dichloromethylene-bis(phosphonic acid) in water and ionic liquids

The complexation of strontium with triisopropyl ester of dichloromethylene-bis(phosphonic acid) (NaL) is examined using ³¹P NMR in water and the hydrophilic ionic liquid 1-butyl-3-methylimidazolium dicyanamide ([BMIM][N(CN)₂]):      

Geometric and electronic structure of an N,N′-ethylene-bis(salicylaldiminato) zinc(II) molecule,ZnO<Subscript>2</Subscript>N<Subscript>2</Subscript>C<Subscript>16</Subscript>H<Subscript>14</Subscript>

Gas electron diffraction at a temperature T of 641(5) K is used to study the structure of an N,N′-ethylenebis(salicylaldiminato) zinc(II) molecule, ZnO₂N₂C₁₆H₁₄, further Zn(salen). The structure of a gaseous Zn(salen) complex has C ₂ symmetry and is characterized by a substantial turn of two chelating fragments of the ligand with respect to each other, and also by a big difference in the length of coordination bonds: r _h1(Zn-O)=1.902(7) Å r _h1(Zn-N)= 2.027(7) Å. Results of the DFT/B3LYP calculation with 6-31G* and CEP,TZV basis sets of the molecule structure well agree with the experimental data. The electronic structure of Ni(salen), Cu(salen), Zn(salen), and Zn(acacen) molecules is considered.     

Study of the electronic structure of Al(III) and Zn(II) complexes with organic ligands by quantum chemistry and photoelectron spectroscopy methods

Photoelectron spectra of aluminum complexes with 8-oxyquinoline (Alq ₃) and zinc complexes with N, N′-(o-phenylene)-bis(salicylidenediamine) (ZnSaloph) were measured on a photoelectron spectroscopy station at the Kurchatov Centre for Synchrotronic Radiation over the range of photon energies from 10 to 100 eV. Thin films of these compounds (∼20 nm thick) prepared by thermal evaporation onto glass substrates covered with transparent electroconductive layer of solid solution of tin and indium oxides (In₂O₃, SnO₂, ITO) were used as the objects of this study. The spectra of the valence band of these compounds and Al 2p level were measured. The data of quantum chemical calculations of the electronic structure obtained by the density functional theory are in good agreement with the experimental photoelectron spectra. Analysis of performance efficiency of the device was carried out on the basis of the results of calculation. This procedure does not result in decomposition of samples in the process of investigation and may be used for studying the electronic structure of coordination compounds with organic ligands in films.