A new method for the synthesis of sulfonated polynaphthylimides

A new method for the synthesis of sulfonated polynaphthylimides has been developed on the basis of the postsulfonation of high-molecular-mass polynaphthylimides with a sulfuric acid-oleum mixture. Sulfonated polymers of this type have been obtained from the polycondensation products of 5-phenylthiophenylene-1,3-diamine with dianhydrides of 1,4,5,8-naphthalenetetracarboxylic acid and 4,4′-(1,4-phenylenedicarbonyl)-bis-naphthalene-1,8-dicarboxylic acid. It has been shown that hydrogen peroxide oxidation of sulfide bridge groups of these polymers in an acidic medium yields high-molecular-mass compounds that contain sulfonic bridge fragments and, therefore, have increased thermal stabilities and enhanced proton conductivities.     

Catalyst-Free Arylation of Tertiary Phosphines with Diaryliodonium Salts Enabled by Visible Light

The visible-light-induced arylation of tertiary phosphines with aryl(mesityl)iodonium triflates to produce the quaternary phosphonium salts occurs under mild, metal, and catalyst-free conditions. Photo-excited EDA complexes between diaryliodonium salts and phosphines supposedly enable this transformation, which is difficult to achieve through the traditional ground-state reactions. Demonstrating high functional group tolerance, broad scope, and complete selectivity of the aryl group transfer, the method is particularly compatible with sterically congested phosphines, which are challenging under metal-based catalytic methods.     

Effect of Radiation on the Supermolecular Structure of Siloxane Block Copolymers with Different Compositions and Block Sizes

-Radiation-induced changes in the supermolecular structure of dimethylphenylsilsesquioxane block copolymers were studied with the use of electron microscopy. It was found that the supermolecular structure of the block copolymers was altered by irradiation. The character of changes depends on the size of a soft, dimethylsiloxane block, as well as on the total amount of the blocks in the copolymer molecule. A variation in the properties of block copolymers upon -irradiation was also detected by the technique of differential scanning calorimetry.     

Degradation of Aqueous Pentadecane Emulsion by an Anodic Microdischarge: 2. Characterization of the Solid Product

The treatment of a pentadecane emulsion in water with a microdischarge at an aluminum valve anode was shown to yield as the major product a polycondensate which forms gas-filled hollow spherical entities. Some properties of the polycondensate were determined and a model for its formation was proposed.     

XIII International Conference on Surface Forces June 28–July 4, 2006, Moscow, Russia

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XIII International Conference on Surface Forces June 28–July 4, 2006, Moscow, Russia     

A nearly complete system of average crystallographic ionic radii and its use for determining ionization potentials

Available systems of empirical (crystallographic) ionic radii are compared. All these systems turn out to be compatible if the O^2? radius is taken to be 0.140 nm. The choice of the oxygen ionic radius is dictated by the equality of the metal ion-oxygen ion distances in oxide crystals and the metal ion-oxygen atom distances in crystal hydrates and concentrated aqueous solutions. In all systems of empirical ionic radii under consideration, the uncertainty of determination of ionic radii is 0.002–0.005 nm. A new method of determination of the ionic radii of elements in unusual valence states is suggested: from the empirical dependence of the electron density at an atom in a given valence state on the atomic radius, a two-parameter equation relating the ionic radii of Period 4–7 elements in two valence states is derived, which allows one to calculate the ionic radius that cannot be determined by crystallography because of the lack of stable compounds in this valence state. Ionic radii are calculated for all Period 4–7 elements in all valence states. They constitute a nearly complete system of ionic radii. There is a linear relationship between the atomic nucleus charge and the inverse ionic radius. It is shown that the square root of the ionization potential is a linear function of the inverse ionic radius. The as yet experimentally unknown ionization potentials of 78 ions of different elements are estimated.     

Ethanol Conversion in an Aqueous Solution upon Aluminum Valve Anode Microdischarge Treatment

The conversion of 0.1–2.0 M aqueous ethanol solutions in the carbonate electrolyte by treatment with a microdischarge at an anode made of the AMg-6 aluminum–magnesium alloy was studied. It was shown that the microdischarge treatment leads to degradation of ethanol yielding hydrogen, carbon monoxide, ₁–₄ hydrocarbons, methanol, formaldehyde, acetaldehyde, 1,2-propylene glycol, 2,3-butylene glycol, water, and acetic acid. The mechanism of relevant processes is discussed, which suggests a multiplicity of ethanol degradation pathways in vapor–gas bubbles.     

Synthesis and Structure of a New Ruthenium(II) Clathrochelate and the Use of a Highly Porous Ceramic Material with an Immobilized Complex in the Oxidative Conversion of Methane

Kinetics and Catalysis - A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the...