Well-Defined Oxide Core-Poly(vinyl pyrrolidone) Shell Nanoparticles: Interactions and Multi-Modal Glass Transition Dynamics at Interfaces

Interfacial interactions and dynamics were studied in silica and alumina core-poly(vinyl pyrrolidone) (PVP) shell nanoparticles with different shell thicknesses starting from 1-2 nm (monolayer); their geometry and structural organization were comprehensively characterized by several techniques. Far- and mid-IR spectroscopy, combined with DSC activation analysis of the glass transition, allowed to register hydrogen bonding and Lewis/Brønsted interactions, and the multi-modal glass transition dynamics in PVP nanoshells, as well as their interrelationship. For PVP monolayer, only a few “abnormal” modes constituted glass transition which covered the temperature range from 80 to 230 °C, with varying the activation energy by an order of magnitude.     

Conversion of Ethanol into a Fraction of C<Subscript>3+</Subscript> Hydrocarbons in the Presence of Gold-Containing Catalysts Based on a Zeolite MFI Support

The results of a study on the activity and operational stability of an Au–Pd/MFI/Al₂O₃ catalyst in the reaction of ethanol conversion into a gasoline fraction of hydrocarbons are reported. In the presence of the Au–Pd/MFI/Al₂O₃ catalyst, ethanol was almost completely converted into an alkane–aromatic fraction of C₃–C₁₁ hydrocarbons at 300°C in an atmosphere of Ar; the yield of this fraction was as high as 90% on a feed carbon basis. It was established that, in the presence of the bimetallic Au–Pd catalyst, the yield of the target fraction increased by 10%, as compared with that on a monometallic Au-containing sample. The Au–Pd/MFI/Al₂O₃ catalyst exhibited much higher stability in a long-term experiment in comparison with the previously tested pilot sample of Pd–Zn/MFI/Al₂O₃. After a 40-h operation, the yield of the target fraction of C₃₊ hydrocarbons in the presence of the Au–Pd/MFI/Al₂O₃ catalyst decreased by 15%. The treatment of the catalyst with hydrogen led to the complete restoration of its activity. The structure of the Au–Pd active constituents was studied by transmission electron microscopy X-ray photoelectron spectroscopy. methods of the and microscopy.     

Effect of Decationation Procedure on the Textural Properties of High-Silica ZSM-5 Zeolite

The texture of the starting high-silica zeolite ZSM-5 and its decationated samples is studied by the low-temperature adsorption method. Mesopores with a diameter of 42 Å are found. Decationation of the zeolite is accompanied by an increase in the specific surface area and pore volume. It is suggested that the textural changes found are due to the removal of admixtures from some pores. A model for the formation of the secondary pore system is proposed. The secondary porosity is suggested to be due to the coordination of the zeolite crystals through the primary particles of aluminum hydroxide located on the surface of the zeolite crystals. The influence of the decationation conditions on the textural characteristics of ZSM-5 is shown.     

Synthesis of Arylidene Derivatives of 1-Aryl-3H-pyrrol-2-ones

The aminolysis of 5-aryl-3-arylidene-3H-furan-2-ones by the action of aromatic amines leads to the formation of substituted amides of 4-oxo acids, the subsequent azacyclization of which in the presence of acetic anhydride leads to the formation of 1,5-diaryl-substituted 3-arylidene-3H-pyrrol-2-ones. The mechanism of the occurring and alternative transformations is discussed.     

Phenylation of Organic Derivatives of Mercury,Silicon, Tin,and Bismuth with Pentaphenylantimony and Pentaphenylphosphorus

Pentaphenylantimony and -phosphorus react with arylmercury chlorides in toluene at room temperature to give diaryl derivatives of mercury in yields of up to 95%. The reactions of pentaphenylantimony and -phosphorus with silicon and tin halides involve arylation of the latter in yields of up to 79%. The products of the reaction of pentaphenylphosphorus with triphenylbismuth dihalides are tetraphenylphosphorus halides, triphenylbismuth, and halobenzene.     

Thermochemistry of Compounds of the MI I(PUO6)2·nH2O Series

The standard enthalpies of formation of uranophosphates M^{I I}(PUO₆)₂·nH₂O (M^{I I} = Mn, Fe, Co, Ni, Cu, Zn, Cd) are determined. The standard enthalpies of the synthesis and dehydration of these compounds are calculated and analyzed.     

Arylmethylene-3H-furan(pyrrol)-2-ones in reactions of [3+2]-cycloaddition with activated hydrazones

Spiropyrrolidine derivatives were synthesized for the first time by [3+2]-cycloaddition of 3-arylmethylene-3H-furan(pyrrol)-2-ones to N-benzylidenebenzylamine activated by the system AcOAg-Et₃N. The reaction route and the spectral characteristics of the first obtained compounds have been discussed.     

3, 6-Di(tert-butyl)-o-benzoquinone fluoroalkylated derivatives

Russian Chemical Bulletin - A reaction of perfluoroalkyltrimethylsilanes with 3, 6-di(tert-butyl)-o-benzoquinone was used to obtain new perfluoroalkyl-substituted sterically hindered...     

Synthesis of bismuth complexes from bismuth iodide and ammonium and phosphonium salts

The complexes [Et₂NH₂] ₃ ⁺ [BiCl₆]^3? (I), [NH₄]⁺[BiI₄(C₅H₅N)₂]^?·2C₅H₅N (II), [Ph₃MeP] ₂ ⁺ [BiI₅]^2? (III), [Ph₃MeP] ₂ ⁺ [BiI₅(C₅H₅N)]^2?·C₅H₅N (IV), [Ph₃MeP] ₃ ⁺ [Bi₃I₁₂]^3? (V), [Ph₃(i-Pr)P] ₃ ⁺ [Bi₃I₁₂]^3?·2Me₂C=O (VI), [Ph₃BuP] ₂ ⁺ [Bi₂I₈·₂Me₂C=O]^2? (VII), and [Ph₃BuP] ₂ ⁺ [Bi₂I₈·2Me₂S=O]^2? (VIII) were obtained by reactions of bismuth iodide with ammonium and phosphonium iodides in acetone, pyridine, or dimethyl sulfoxide.     

Amidation of deltacyclene and hexacyclic norbornadiene dimers with acetonitrile and water catalyzed by FeCl3·6H2O

Abstract

FeCl₃·6H₂O-catalyzed Ritter amidation of deltacyclene and hexacyclic norbornadiene dimers containing both a double bond and a three-carbon ring in the molecule with acetonitrile and water was performed. Depending on the hydrocarbon structure, the reaction proceeds via C-C bond cleavage in the three-carbon ring or at the double bond to form the corresponding N-acetamides.