Determination of chemisorbed metals on planar fused-silica surfaces using thermal lens spectrometry

Thermal lens spectrometry was used to determine the surface concentrations of metals on planar fused-silica surfaces modified with the use of vanadium(V) oxochloride, tin(IV) tetrachloride, and titanium(IV) oxochloride after complexation reactions with 4-(2-pyridylazo)resorcinol and 2-thiazolylazopyrocatechol from aqueous solutions. The surface concentrations of vanadium and titanium found from thermal lens experiments (8 × 10^?11 and 6 × 10^?10 mol/cm², respectively) correlate well with those theoretically calculated based on monolayer and bilayer approximations for metal-containing groups, respectively. The coverage uniformity and the concentration of a chemisorbed substance on a glass surface were evaluated.     

Viscosity of dilute solutions of styrene copolymers in the course of polymer-analogous transformations

The properties of dilute solutions of styrene copolymers and their porphyrin derivatives prepared via the functional group transformations have been studied in DMF at 20–35°C. The effect of the copolymer composition, on the intrinsic viscosity, the Huggins constant, the macromolecule dimensions, and thus on the interaction with solvent has been elucidated. The nature and content of functional groups in the polymer influence the behavior of macromolecule coil in the solution. Introduction of the porphyrin fragment loosens the macromolecular coil, but does not qualitatively change the solution behavior.     

Synthesis and spectral properties of lutetium complexes with unsymmetrical phthalocyanines and sandwich complexes based thereon containing tetraanthraquinonoporphyrazine fragments

Joint condensation of 4,5-bis(4-hexadecyloxyphenoxy)phthalonitrile (A) and tetrachlorophthalonitrile (B) in boiling hexan-1-ol in the presence of lithium hexan-1-olate and subsequent reaction with LuCl₃ · 6 H₂O gave single-decker lutetium complexes with unsymmetrical phthalocyanines (AABB, ABAB). Reactions of the latter with 9,10-dioxo-9.10-dihydroanthraquinone-2,3-dicarbonitrile afforded mixed-ligand double-decker lutetium complexes containing tetraanthraquinonoporphyrazine as one of the ligands. Spectral properties of the synthesized complexes were studied, and all complexes were found to exhibit red fluorescence.     

Application of the theory of dilute polymer solutions to the assessment of the structure and properties of styrene-acrylic acid copolymers

Properties of dilute solutions of polystyrene and styrene-acrylic acid copolymers in DMF and ethyl acetate were studied in the temperature range 20–35°C. It was shown that the dependences of the intrinsic viscosity and Huggins constants on temperature for the copolymers differ from that for polystyrene. Comparison of the “quality” of the solvents was carried out.     

Mechanism and Kinetics of the Sorption of Platinum, Palladium, and Gold on Activated Carbon from UV-Illuminated Chloride Solutions

The mechanism and kinetics of the sorption preconcentration of gold, platinum, and palladium on activated carbon from solutions exposed to ultraviolet (UV) radiation were studied. The thermodynamic parameters of sorption (sorption capacity and type of adsorption isotherm) were determined; the effect of pH was considered. An explanation of the mechanism of the effect of UV illumination on sorption preconcentration was proposed. It was demonstrated that UV illumination does not change thermodynamic parameters of sorption but significantly affects the kinetics of sorption preconcentration.     

Reaction of N-acetoxymethylacetamide and N-acetoxyme thylbenzamide with ester-amides and amides of phosphorous acid

Conclusions Mono-, di-, and triamidophosphites react with N-acetoxymethylacetamide and N-acetoxymethylbenzamide at the phosphorus atom and at the nitrogen atom. In the reactions with N-acetoxymethylacetamide the fraction of the product of attack at the nitrogen atom is higher than in the reactions with N-acetoxymethylbenzamide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1620–1623, July, 1982.