A 2D Network in Co-Crystal (1:1) Based on <Emphasis Type="Italic">trans</Emphasis>-[PtBr<Subscript>2</Subscript>(Acetoxime)<Subscript>2</Subscript>] and 18-Crown-6

Abstract  

A 1:1 co-crystal of trans-[PtBr₂(acetoxime)₂] and 18-crown-6 has been obtained by a slow-evaporation of the equimolar mixture of trans-[PtBr₂(acetoxime)₂] and the crown ether. The compound crystallizes in the triclinic space group P [`1] P\,\bar{1} , with unit cell parameters a = 7.4765(2) Å, b = 9.5044(2) Å, c = 10.1591(3) Å, α = 83.687(1)°, β = 70.847(1)°, γ = 79.773(1)°, Z = 1. trans-[PtBr₂(acetoxime)₂] is assembled with 18-crown-6 into a 2D network structure by interactions between the oxygen atoms of 18-crown-6 and the hydroxylic and methyl hydrogen atoms of the oxime ligands.     

Measurement of the temperature distribution on the surface of the laser heated specimen in a diamond anvil cell system by the tandem imaging acousto-optical filter

We demonstrate that combining the laser heating (LH) system in a diamond anvil cell (DAC) with a tandem acousto-optical tunable filter (TAOTF) allows measurement of the temperature distribution (TD) under infrared (IR, 1064?nm) LH of a specimen under high pressure in a DAC. The main component of the system is a TAOTF synchronized with a video camera. The system allows TD mapping within a temperature range of approximately 1000–2000?K on the surface of a laser-heated object (Fe plates) at high pressure in a DAC with a spatial resolution 2?µm by fitting the actual signal to Planck’s equation at each point.     

Far fields of the surface disturbances produced by a pulsating source in an infinite-depth fluid

The problem of constructing uniform asymptotics for the far fields of surface disturbances produced by a localized pulsating source in a heavy homogeneous infinite-depth fluid is considered. The wave pattern of the excited fields is the sum of waves of two types, namely, annular and wedgeshaped. The solutions obtained describe the wave disturbances far from the pulsating source both inside and outside the Kelvin wave wedges.     

Absorption and scattering in bismuth-doped optical fibers

The optical-loss spectra of bismuth-doped aluminosilicate glass core optical fibers have been investigated in the spectral range 200–1700 nm. Absorption (active and inactive) and scattering losses have been separated. The optical fibers under study were fabricated by methods of modified chemical vapor deposition and surface-plasma chemical vapor deposition.     

Photochemical study of anthracene crystallites by Fourier transform spectroscopic imaging.

Fourier transform-based spectroscopic imaging was used for direct, time-resolved, analysis of UV-irradiated anthracene crystallites. Well-resolved fluorescence spectra were obtained at a spatial resolution of 1 microm. The appearance of such photochemical by-products as dianthracene and anthraquinone was monitored throughout the irradiation experiments. Under deaerated conditions, photolysis of anthracene was accompanied by formation of dianthracene. When performed under aerated conditions, however, the spectral data indicated formation of both dianthracene and anthraquinone. Spectral features obtained for the directly monitored photolysis of anthracene are discussed in respect to the structural and compositional modifications in such crystallites. Capabilities of the spectral imaging device for the quantification of the photochemical products of anthracene are discussed.     

Existence and uniqueness of solutions to weakly singular integral-algebraic and integro-differential equations

We consider systems of integral-algebraic and integro-differential equations with weakly singular kernels. Although these problem classes are not in the focus of the main stream literature, they are interesting, not only in their own right, but also because they may arise from the analysis of certain classes of differential-algebraic systems of partial differential equations. In the first part of the paper, we deal with two-dimensional integral-algebraic equations. Next, we analyze Volterra integral equations of the first kind in which the determinant of the kernel matrix k(t, x) vanishes when t = x. Finally, the third part of the work is devoted to the analysis of degenerate integro-differential systems. The aim of the paper is to specify conditions which are sufficient for the existence of a unique continuous solution to the above problems. Theoretical findings are illustrated by a number of examples.     

Flow-injection photometric determination of mercaptans in light oil products with chromatomembrane extraction

A procedure was developed for the flow-injection photometric determination of mercaptans in light oil products. The use of sodium nitroferricyanide as the photometric reagent at 540 nm provides a detection limit of mercaptan sulfur of 0.3 mg/L at a volume of the sample of 3 mL; the analytical range is from 1 to 50 mg/L.     

Selective photometric determination of selenium in aqueous media

A procedure is developed for the photometric determination of selenium in aqueous media using 2-(p-nitrophenyl)-3,5-diphenyltetrazolium chloride. To selectively determine selenium, a two-stage scheme of sample preparation is chosen. It includes the gas extraction of selenium liberated as hydrogen selenide, its extraction from the gas phase to a solution of lead nitrate by liquid absorption and repeated extraction of hydrogen selenide, followed by its absorption with an aqueous reagent solution to form water-insoluble formazan. The formazan is extracted with chloroform. The concentration of selenium is determined from the absorbance of the chloroform extract of formazan. The procedure involves no special preconcentration operations and allows from 10 to 100 μg/L selenium to be determined.