Electrochemical Reduction of Spirocyclopentylmalonyl Peroxide in an Aqueous Medium

Russian Journal of Physical Chemistry A - The electrochemical reduction of spirocyclopentylmalonyl peroxide in an aqueous medium is studied via cyclic voltammetry on a gold stationary electrode....     

Synthesis of Ultrafine Metallic Copper Nanocubes Using Ethanol-Ionic Liquid Approach

Ultrafine metallic copper nano-cubes were synthesized by reduction of copper nitrate by superheated ethanol in 1-Butyl-3-methylimidazolium hexafluorophosphate ionic liquid environment. Nanocubes were characterized by X-ray powder diffraction, transition electron microscopy and X-ray photoelectron spectroscopy. Since all resources are environmentally-friendly substances, the presented procedure is highly sustainable and may be useful for numerous applications.     

Dimethylmalonoyl peroxide – the neglected lowest homologue: simple synthesis and high reactivity

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The first results of observations of acoustic signals generated by cosmic ray muons in a seismically stressed medium

The first results of observations of acoustic signals generated by high-energy muons of extensive air showers, which propagate in a seismically stressed medium are presented. The cosmophysical method for monitoring the volume stressed state is tested using the experimental setup developed in the earthquake-prone region of Almaty at the Tien Shan High-Altitude Scientific Station of the Lebedev Physical Institute. High-amplitude acoustic signals correlated with the passage and interaction of muon groups in the Earth’s crust are detected for the first time.     

Determination of gold by atomic absorption spectrometry after extraction into the non-desulphurized fraction of crude oil distillate

The extraction of gold from aqueous chloride solutions into non-desulphurized fractions of crude oil distillates, especially paraffin oil, is described. The fraction boiling at 150–220°C exhibited optimum properties. The extraction is tested for solutions containing chlorides, dissolved chlorine and 0.1–3 M hydrochloric acid. Nitric acid should be absent. The distribution coefficient of gold varies from 400 to 900. Extracts containing ? 0.3 g l^?1 gold are stable for at least 12 months. The organic extract is sprayed into a lean acetylene/air flame with measurement at 242.8 nm (background correction). The calibration graph has linear portions over the ranges 0–2.5 and 2.5–16 mg l^?1. The limit of detection is 0.03 mg l^?1 gold in the extract (0.001 mg l^?1 in the aqueous phase). The minimum measurable concentration for gold in auriferous rocks and ores is 0.018 g per ton with 25-g samples.     

EPR study of (η5-cyclopentadienyl)nickel(I) complexes with P-and N-Donor ligands and 1,5-cyclooctadiene

Mononuclear (η⁵-cyclopentadienyl)nickel(I) complexes with triphenylphosphine, triethylphosphite, 2,2’-bipyridyl, and 1,5-cyclooctadiene formed in the course of reduction of nickelocene were studied by EPR method. Monocyclopentadienyl Ni(I) complexes of the composition CpNiL₂ were shown to form during nickelocene reduction irrespective of the method applied (the use of organometallic compound, alkali metal, thermal conditions) in the presence of stabilizing ligands L (L = PPh₃, P(OEt)₃, Bipy/2, COD/2) and in the course of contradisproportionation reaction between nickelocene and the corresponding NiL₄ complex. It was found that in the structure of these CpNiL₂ complexes (L = PPh₃, P(OEt)₃, Bipy/2), the main molecular axis is perpendicular to the L-Ni-L plane and these complexes should be considered as derivatives of trigonal structures of D _3h symmetry distorted by Cp ligand. In CpNi(COD) complex, the main axis passes through the Cpring center and this complex should be treated as a derivative of pentagonal structure of C _5v symmetry distorted by COD ligand. Nonequivalence of ³¹P nuclei results from vibronic interaction effect in tricoordinate structures in pseudodegenerate electron state (Jahn-Teller effect).     

Polyacrylamide gel electrophoresis of proteoglycans in large-pore gradient gels

A procedure is described for preparing large-pore polyacrylamide gradient gels (1.2–16% T, 10–4% C) that allow the separation of large proteoglycans of molecular mass up to several millions.     

Electrical conductivity of carbon fibres/polyester resin composites in the percolation threshold region

The electrical conductivity of composites of a polyester resin filled with short carbon fibres has been investigated with a special attention to the properties in the percolation threshold region. A very low percolation threshold (0.7-0.8 vol% of the filler) was confirmed. In contrast to S-shaped curves calculated according to the percolation theory of composites of globular particles, the experimental conductivity vs. fibre content dependence, after a steep increase in the percolation region, increased almost linearly. This atypical behaviour was explained by a different mechanism of formation of fibrous and globular conducting structures above the percolation threshold. An increase in scatter of conductivity values observed at percolation threshold as a consequence of great fluctuation of fibre arrangement manifested itself also in the conductivity-temperature dependences.