A new method for the generation of stable phenoxyl radicals by the reaction of [(Me3Si)2N]2E (E = Ge,Sn) with sterically hindered phenols

An unusual reaction of diaminogermylene and diaminostannylene with sterically hindered phenols which leads to the formation of stable phenoxyl radicals in high concentrations was found. The reaction mechanism was proposed. Amides [(Me₃Si)₂N]₂E (E = Ge, Sn) were investigated electrochemically.     

Preparation and reactivity of metal-containing monomers

Russian Chemical Bulletin - The monomer [Cr3O(OCOCH=CH2)6]OH was produced by reaction of acrylic acid with fresh chromium hydroxide. This monomer was investigated by a number of physicochemical...     

Intracavity laser polarization spectrometer for biomolecule traces

A polarization variant of an intracavity laser spectrometer based on the competition of beams in an argon ion laser, radiating a number of narrow lines in the 275 to 529 nm spectral range, is proposed and described for the spectral analysis of liquid samples, having broad absorption bands, mainly biomolecules in solutions. By careful optimization of the operating conditions, a procedure has been established that results in a minimal measurable absorbance decreased up to 10(-5) units of optical density. The examined spectrometer provides a wide dynamic range of analysis. A determination of trace contents of amino acids in methanol were carried out.     

Photochemical properties and structures ofN-amino andN-azomethine derivatives of 2,4,6-triphenylpyridinium perchlorates

The molecular structures of the initial compounds and the products of photocyclization involving amino and azomethine groups in perchlorates ofN-amino (1) andN-azomethine (2) derivatives of 2,4,6-triphenylpyridinium cations were studied. Cations1 and2 have an essentially non-coplanar arrangement of the -Ph rings, and the product of photocyclization of2, cation3, is characterized by a flattened structure. It was found that the orientation of the lone electron pair of the N atom with respect to one of the planes of the -Ph rings in molecule1 is more favorable for monocyclization involving the amino group. The structure of molecule2 allows two routes of the photoreaction,viz., O N proton transfer and monocyclization with an -Ph ring. However, the structural features of molecule2 are more favorable for photocyclization.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 296–301, February, 1995.     

Effect of Treatment with Carbon Dioxide of the Zn Form of the TsVK Zeolite on Its Acid and Catalytic Properties in the Conversion of Methanol to Hydrocarbons

It is shown that it is possible to increase the yield of liquid hydrocarbons of the benzene fraction in the Mobil process by use of a catalyst modified by treatment with CO₂ of the Zn form of the TsVK zeolite. It is established that on treatment with CO₂ of the Zn-TzVK zeolite the concentration of strongly acidic -centers is increased. As a result of alkylation of C₂-C₄ olefins by methanol at these sites more of the high molecular C₅-C₈ aliphatic hydrocarbons are formed. Selectivity of conversion of methanol to liquid C₅-C₁₀ hydrocarbons of the benzene fraction is increased, but selectivity with respect to the light C₂-C₄ fractions is decreased.     

Hydrogen bonded clusters of alcohol molecules in inert solvents: a chain statistics approach

A theory is proposed for modeling the autoassociation of alcohol molecules either in the neat liquid or in inert (non-complexing) solvents. This autoassociation by hydrogen bonds takes the form of clusters which can be predominantly open or cyclized chains, depending on the concentration. Chain conformation statistics are used for calculating the dipole moment of each type of chain. Cyclization equilibrium theory is employed for obtaining formulae for the fraction of all types of clusters. The total Kirkwood angular correlation factorg is calculated in function of the concentration. For this only two parameters are used; the first one is a common equilibrium constant for H bond dissociation; the second one is closely linked to the stiffness of the chains. A numerical illustration is presented for the case of normal hexanol in various aliphatic solvents, for which several dielectric data exist in the literature.