Study of air pollution particulates by X-ray photoelectron spectroscopy

Summary This paper discusses the application of X-ray photoelectron spectroscopy to the determination of the chemical composition of sulfur and nitrogen species in air pollution particulates. Core electron chemical shift measurements are augmented by the determination of relative concentrations and volatility of particulate species.

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Untersuchung von Verunreinigungsteilchen in der Luft durch Röntgenphotoelektronen-Spektroskopie

Zusammenfassung Die Anwendung der Röntgenphotoelektronen-Spektroskopie auf die Bestimmung der chemischen Zusammensetzung von Schwefel und Stickstoff enthaltenden Verunreinigungsteilchen in Luft wird diskutiert. Messungen der chemischen Verschiebung werden ergänzt durch die Bestimmung der relativen Konzentrationen und der Flüchtigkeit der Verbindungen.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

Crystal and molecular structure, and P N.M.R. characteristics of di-μ-chlorodi(propionyl)bis(dimethylphenylphosphine)diplatinum(III). Trans-influence of ligands in binuclear complexes

The known complex, $\text{trans}$-(η-C₅H₅)₂Rh₂(CO)₂(CF₃C₂CF₃) is formed in high yield from (η-C₅H₅)Rh(CO)₂ and CF₃FCCF₃ at 100°. The less stable $\text{cis}$-isomer of the complex is obtained in low yield from the same reaction. The infrared, ¹H, ¹⁹F and ¹³C NMR spectra of the two isomers are compared. The $\text{trans}$-isomer undergoes CO scrambling in solution at room temperature, and the variable temperature ¹³C NMR spectra are consistent with a pairwise bridge opening and closing mechanism. The mechanism is extended to account for the isomerization of $\text{cis}$ to $\text{trans}$ isomer, whihc has a half-life of 12 h at room temperature. The ¹³C spectrum indicates that the $\text{cis}$-isomer is static in solution at room temperature. The $\text{trans}$-isomer is reversibly protonated by protonic acids, and BF₄^? and PF₆^? salts of the protonated species can be isolated. The spectroscopic properties of these salts are consistent with protonation at one of the alkynyl-carbons, but it is not possible to distinguish between two alternative structures for the complex cation.Treatment of (η-C₅H₅)₂Rh₂(CO)₂(CF₃C₂CF₃) with (η-C₅H₅)Rh(CO)₂ gives the trinuclear complex (η-C₅H₅)₃Rh₃(CO)(CF₃C₂CF₃) in 80% yield. The analogoug but-2-yne complex is formed from (η-C₅H₅)₃Rh₃(CO)₃ and MeCCMe. The infrared, ¹H, ¹⁹F and ¹³C NMR spectra indicate that the hexafluorobut-2-yne complex exists in two different structural arrangements in solution. One has an edge bridging, and the other a face bridging carbonyl. The proportion of the isomers is affected by the solvent polarity. The spectra of the but-2-yne complex indicate it is fluxional at room temperature, and has a face bridging structure in solution regardless of the polarity of the solvent. Reversible protonation of the hexafluorobut-2-yne complex occurs in protonic acids, and the salt [(η-C₅H₅)₃Rh₃(CO)(CF₃C₂CF₃)H]⁺[BF₄]^?,H₂O can be isolated. The spectroscopic properties of this complex are consistent with a structure incorporating an edge-bridging carbonyl, and probably, an edge-bridging hydride ligand.     

Formation of Flocs and Sediments in the Presence of Cationic Polyelectrolytes

Regularities of the flocculation of kaolin suspension with cationic polyelectrolytes based on 1,2-dimethyl-5-vinylpyridinium methyl sulfate were studied by turbidimetry, optical microscopy, and sedimentation methods. It was found that poly(1,2-dimethyl-5-vinylpyridinium methyl sulfate)-co-N-vinylpirrolidone promotes the formation of dense flocs and provide a complete sedimentation of the kaolin suspension at a high rate. The effect of dense floc formation is likely caused by a copolymer hydrophobicity and a compression of adsorbed macrocoils accompanied by squeezing of a dispersion medium out of interparticle space.     

Rheokinetic features of the initial steps of curing of oligodiene-urethane prepolymer with a hydroxyl-containing curing agent at equimolecular ratio of the reactive groups

Rheokinetic studies of curing of oligodiene-urethane prepolymer with a hydroxyl-containing curing agent at the molar ratio NCO/OH = 1.0 were performed. In the initial step of curing, catalyltic formation of polydiene-urethane follows a second-order equation, whereas the urethane formation step is adequately described by a kinetic equation with an autoacceleration effect.     

Investigation of the effect of catalysts on the foaming parameters of compositions and properties of elastic polydieneurethane foams

The results of investigations on the establishment of the interrelations between the foaming parameters and properties of polydieneurethane foams are presented. It is shown that the combined application of tertiary amines and organotin compounds as catalysts for urethane formation allows attainment of synchronization of kinetic parameters, which facilitates the production of materials with a uniform fine meshed structure and improved physicomechanical properties.     

The influence of a fluoroorganic modifier—stillage residues of alcohol-telomeres—on properties of filled poldienurethanes

The results of an investigation of the influence of stillage residues of polyfluorinated alcoholtelomeres on the properties of polydienurethane compositions and elastomers based on them are presented. It is shown that such modification allows one to raise the sedimentation stability of the compositions and increase the characteristics of physicochemical and dynamic properties of elastomers.     

Rheological properties of associates of ionic monomers with micelles of oppositely charged surfactants

Rheological properties of associates formed by interaction of trimethyl[methacryl-oxyethyl]ammonium methyl sulfate with sodium octyl- and dodecyl sulfate micelles, as well as associates of sodium 4-styrenesulfonate with dodecyltrimethylammonium bromide micelles in aqueous solutions were studied by steady shear and oscillatory (dynamic) shear measurements with Fourier transform. It was shown that viscosity depends on the composition and achieves maximum value at equimolar ratio of components for two of studied systems. The extremal dependence of the viscosity vs. composition is not observed for systems with sodium octyl sulfate due to weak interactions between the components. The systems exhibiting the anomalous dependencies of concentration to viscosity are viscoelastic fluids due to the physical entanglements between the associates.     

On the stabilization and methods for modification of nanosize particles used for the preparation of polymer-inorganic nanocomposites

Data on the methods of stabilization and modification of nanosize particles used in the technology of development of new polymer-inorganic nanocomposites were analyzed and generalized. Advantages of the chemical method using silane-based surface-binding modifiers were discussed. The use of surface-initiated graft polymerization was shown to be promising for the solution of problems of deagglomeration, stabilization, and efficient homogenization of nanosize particles.     

Effect of adamantane-containing additives on the isomerization of n-heptane in the ionic liquid trimethylammonium hydrochloride-aluminum chloride

We study the effect of adamantane-containing additives on the process of isomerization of n-heptane in the ionic liquid trimethylammonium hydrochloride-aluminum chloride (1 : 2 mol). It is shown that introducing 1-cyanomethyl-3-cyanoadamantane (5.0 wt %) into the reaction mixture slows conversion and lowers the yield of iso-products by a factor of more than 1.5, while adding adamantylpolyimide (0.5–5.0 wt %) substantially accelerates the isomerization of n-heptane and increases the yield of iso-products. In addition, this reaction proceeds under mild conditions at 40°C in the absence of hydrogen and precious metals.     

Synthesis and evaluation of properties of the optically transparent (co)polyimides based on cyclic and alicyclic diamines and dianhydrides of aromatic tetracarboxylic acids

Russian Chemical Bulletin - Optically transparent polyimides (PIs) containing adamantane moieties in the structure of diamine unit were synthesized, and their properties were evaluated. The...