Synthesis and structure of complex compound Rh(III) of (NH4)2[Rh(NO2)3(NH3)(µ-OH)]2 composition

The crystalline structure of a new compound Rh(III) of (NH₄)₂[Rh(NO₂)₃(NH₃)(μ-OH)]₂ composition has been determined. The crystallographic characteristics are H₁₆N₁₀O₁₄Rh₂: a = 6.3963(2) Å, b = 9.3701(4) Å, c = 13.6646(5) Å, β = 102.266(1)°, V = 800.28(5) ų, Z = 2, d _calc = 2.432 g/cm³. The distance Rh...Rh in the dimer is 3.200 Å. Original Russian Text Copyright ? 2006 by S. P. Khranenko, I. A. Baidina, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 2, pp. 380–384, March–April, 2006.     

Sodium aluminum hydride reduction of organic compounds in hydrocarbon media

Summary The reduction of complex esters and carbonyl compounds in hydrocarbon media by aluminum hydrides of the alkali metals results in the formation of the corresponding alcohol in high yield. The reduction of nitriles proceeds with the formation of primary amines.     

Liquid-phase oxidation of tert-butyldimethylsilane

Kinetics and mechanism of liquid-phase oxidation of tert-butyldimethylsilane t-BuMe₂SiH with molecular oxygen in the temperature range 297–350K were studied. Reaction orders in silane, initiator, and oxygen were evaluated. The major product of the oxidation of t-BuMe₂SiH is tert-butyldimethylsilyl hydroperoxide t-BuMe₂SiOOH. It was shown for the first time that the major reaction product is a silyl hydroperoxide. A kinetic scheme of the oxidation of t-BuMe₂SiH is offered and discussed.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1625–1630.Original Russian Text Copyright © 2004 by Lutsik-Maksim, Timokhin, Zaborovskii, Pristanskii, Turovskii, Chatgilialoglu.This revised version was published online in April 2005 with a corrected cover date.     

Configurational bias Monte Carlo simulation of phase segregation in block copolymer networks

Cross-linked block copolymers are used as adhesives in fiber-reinforced composite material manufactures for automotive applications. Good adhesion between the polymer matrix and fibers in the interphase region is required for the structural integrity of these materials. Experimental evidence indicates that superior adhesion is obtained when phase segregation occurs between the two matrix phase block copolymers. It is therefore desirable to predict the conditions under which phase segregation is expected to occur. Configurational bias Monte Carlo simulations of two-component, trifunctional block copolymer networks were carried out to investigate phase segregation in these materials. The effects of four principal parameters on phase segregation were examined: the weight fractions of the two components, the cross-link length, the connectivity of the network, and the ratio of the square-well interactions. The molecular simulation results confirmed trends observed in laboratory measurements.     

Reactions of O2 --Containing Supramolecules with Alkyl Halides

Formation of O₂ ^--containing supramolecules generated from the system 18-crown-6-KO₂ and electrochemically (tetraethylammonium superoxide) and the kinetics of the reactions of the generated O₂ ^- with alkyl halides in acetonitrile were studied conductometrically and UV-spectrophotometrically; the kinetic parameters of the processes were determined. The E2 mechanism was suggested for the reaction.     

New method of preparing β-lactams

Summary A method has been devised for the synthesis of -lacrams from amides of -ha!ocarboxylic acids. Some new azetidinones with residues containing carboxyl groups on the nitrogen have been piepated. The method permits the conversion of $-amino acids trio difficulty accessible mixed (secondary) amino acids.This paper is publised under the regulations governing Brief Communications.     

Synthesis and modification of 4-hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline

4-Hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline was prepared by O-allylation of 4-hydroxy-2-methylquinoline followed by the Claisen rearrangement of the 2-methyl-4-(2-chloro-2-propenyloxy)quinoline obtained. Chemical modifications of 4-hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline resulted in the synthesis of 4-amino-2-methyl-3-(2-methyl-3-indolyl)quinoline.     

Voltammetry of Formaldehyde at Mechanically Renewable Solid Electrodes

The electrochemical behavior of formaldehyde (CH₂O) at solid electrodes made of platinum, gold, silver, cobalt, nickel, copper, and graphite was studied. The working surface of the electrodes was renewed by cutting a thin layer (0.5 m) immediately in the test solution. It was found that, in alkaline solutions, CH₂O was oxidized at all electrodes other than cobalt and graphite ones while scanning the potential to the anode and cathode regions. The peaks of CH₂O oxidation at platinum and gold electrodes using potential scanning in the anode and cathode directions, as well as at nickel, copper, and silver electrodes using potential scanning in the anodic direction, are suitable for analytical purposes.     

Separation and quantitative determination of dioxouranium(VI) and thorium(IV) ions in the presence of different metallic ions by TLC using iso-propyldithiophosphoric acid as complexing agent

The separation of uranium and thorium from matrices containing various metal ions, was studied. The mobile phase contains isopropyldithiophosphoric acid (i-PrDTP), as a complexing agent, in order to differentiate the studied species by modifying their retention. The paper reports the successful separation and the quantitative determination of uranium and thorium in the presence of Ni²⁺, Co²⁺ and Ag⁺ in the concentration range 2.5–2.5 μg/μl for uranium and 2.5–30 μg/μl for thorium.     

Thermodynamic properties of water/organic systems with small contents of water 1. Limiting partial molal volumes of D2O and H2O in methanol and 2-propanol at various temperatures

Limiting partial molal volumes of D₂O and H₂O in methanol and 2-propanol have been measured in the temperature interval 278–318 K. A hypothesis is advanced regarding the formation of water-alcohol aggregates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 317–320, February, 1991.