Quantitative structure-property relationship: XXVII. Estimation of the free energy of formation of host-guest complexes of α-cyclodextrin with benzene derivatives

A structure-property relationship was used to estimate the free energy of formation of host-guest complexes of α-cyclodextrin with monosubstituted benzene and phenol derivatives and with symmetrical 1,4-disubstituted benzene derivatives, in which various nonvalent interactions (hydrophobic, van der Waals, donor-acceptor) play a significant role. The calculated values are well consistent with the experiment.     

Effect of Thiourea on the Kinetics of the Hydrogen Evolution Reaction at Iron and the Transport of Hydrogen through a Steel Membrane in Solutions of C<Subscript>2</Subscript>H<Subscript>4</Subscript>(OH)<Subscript>2</Subscript>-H<Subscript>2</Subscript>O-HCl

The effect of thiourea (0.5–10 mM) on the kinetics of the hydrogen evolution reaction (HER) at iron and the hydrogen transport through a steel membrane out of ethylene glycol (containing 2 and 10 wt % H₂O) and aqueous solutions containing HCl (0.1–0.99 M) with a constant ionic strength equal to unity is studied in parallel experiments. The presence of 0.5 mM of thiourea in the solutions raises the overvoltage of hydrogen evolution, while a subsequent increase in its concentration does not effect the HER kinetics. The dependence of the flux of hydrogen diffusion through the membrane on the thiourea content passes through a maximum.     

Synthesis of H (type 4) trisaccharide,key structural fragment of globo-H and fucosyl-GM1 cancer-associated antigens

A convenient synthesis of Fucα1-2Galβ1-3GalNAcβ-OCH₂CH₂CH₂NH₂ (trisaccharide H type 4) is described. This glycan is the terminal part of glycosphingolipids globo-H and fucosyl-GM1 known as cancer-associated carbohydrate antigens.     

Origin of Porous Silicon Photoluminescence Peaks in the Wavelength Range 460–700 nm

The change in the photoluminescence peaks of porous silicon at λ = 640–670 and 540–560 nm at 300 and 77 K, as well as their behavior after low-temperature annealing of the samples at 500°С, has been studied. The change in these peaks correlated with that in the IR spectra. The peak at 640–670 nm has been explained by the existence Si–OH groups on the porous silicon layers and the peak at 540–560 nm, by the photoluminescence of the silicon matrix per se.     

Structure-Property Correlation Equation: VII. Some Properties of Perfluorinated Organic Compounds

The possibilities were demonstrated of using a simple structure-property correlation equation for estimation of physicochemical properties of organofluorine compounds: boiling points, heats of vaporization, factors octanol-water partition, saturated vapor pressures, and also, for the compounds used as blood substitutes, times of half-elimination from body.     

Physicochemical modeling of the behavior of impurities in bismuth oxide in the chemical distillation of the sample matrix

The physicochemical modeling of the behavior of impurities in the course of their preconcentration by the chemical distillation of the sample matrix consisting of granules of a solid solution of impurities in bismuth oxide was carried out. It was supposed that the distillation process is conducted in a kinetic mode. The results of calculations by the model are compared with the earlier results of modeling of the behavior of impurities in distilling a heterophase sample consisting of matrix (bismuth oxide) granules and granules of impurity oxides. The experimental data and results of calculations by the model agree well.     

Inhibition of Corrosion and Hydrogenation of Carbon Steel with a Number of Inhibitors in Weakly Acid Media Containing H<Subscript>2</Subscript>S and CO<Subscript>2</Subscript>

The inhibitive power of AMDOR IK-7 formulation, homologous mixture of alkyl ammonium acetates C₁₀–C₁₄ in a specific solvent, and PKU-6 toward corrosion of St. 3 steel in weakly acid media containing 5.8 g l^?1 NaCl, H₂S, and CO₂ was studied. The influence exerted by the inhibitors on the kinetics of partial electrode reactions and on the hydrogenation of steel was examined. Impedance spectra were recorded and analyzed.     

Using of Fractional Separation for the Analysis of MoO<Subscript>3</Subscript> by Atomic Emission Spectrometry with Inductively Coupled Plasma and Electrothermal Vaporization

The introduction of various forms of molybdenum into an inductively coupled plasma was studied in the vaporization of solutions from a graphite tube. A temperature program is selected that enables the separated vaporization of analytes and molybdenum (matrix) for atomic emission spectrometry with inductively coupled plasma and electrothermal vapoization (ETV–ICP–AES) analysis. The limits of detection for analytes in the ETV–ICP–AES analysis of molybdenum trioxide are evaluated using the fractional separation of analytes and the matrix.