Computer processing of electronic absorption spectra of rare-earth elements in inorganic laser media

Algorithms and program modules are developed for calculation of the Judd-Ofelt parameters on modern computers. These programs can be used to perform numerical analysis of the energy absorption by rareearth ions in laser media.     

Synthesis and Transformation of 5- and 2-Methyl- bicyclo[2.2.1]hept-2-enes and 2-Methylenebicyclo[2.2.1]heptane with Retrospective δ-Migration of Hydrogen over Oxide Catalyst

5-, 2-Methylbicyclo[2.2.1]hept-2-enes, 2-methylenebicyclo[2.2.1]heptane were synthesizedby a new procedure, and their transformations in a flow system over stationary layer of aluminosilicatecatalyst were studied at various temperatures. At 150-400°C these compounds undergo isomerization which is accompanied by -migration of hydrogen. The isomerization mechanism is discussed in terms of formation of classical carbocations, not invoking nonclassical carbenium ion.     

Addition of thiophenols to N-vinylpyrroles

Thiophenols add to 1-vinyl-4,5,6,7-tetrahydroindole and 1-vinyl-2-phenylpyrrole in the presence of azobisisobutyronitrile to form 1-(2-arylthioethyl)pyrroles. The major products in the absence of initiator are the isomeric 1-(1-arylthioethyl)pyrrole -adducts. NH-Pyrroles inhibit the radical process and form selectively the -adducts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 750–752, June, 1990.     

EPR determination of the rate constants of detachment of hydrogen from triethylsilane by metal carbonyl radicals

Conclusions The rate constants of detachment of hydrogen from triethylsilane by radicals of rhenium and manganese pentacarbonyls, tungsten cyclopentadienyltricarbonyl, and iron eyclopentadienyldicarbonyl were determined, and the order of the reactivity of the metal carbonyls was hypothesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1981–1987, September, 1986.     

Conformational analysis of spiranes. Part III

Spiro[5.5]undecane,1, and its oxa analogues,2, exemplify ambiguities in the domain of chirality. Low temperature¹H and¹³C NMR measurements of tetraoxaspiroundecanes3–5 provide an unusual opportunity for detection of largely neglected effects of the chirality of the frozen conformations of these molecules. For the trispiro compound,5, two dynamical processes are detected upon temperature lowering: cyclohexane and dioxane ring inversion. At low temperatures, it is possible to detect diastereoisomerism of5 due to the existence of three elements of chirality in the molecule.For Parts I and II see ref. [1].     

Spin-adducts of radicals ·P(O)(OPri)2 and ·CMe3 with pyrrolidino[60]fullerenes studied by ESR spectroscopy

The addition of the ^·Bu^t (R¹) and ^·P(O)(OPrⁱ)₂ (R²) radicals to pyrrolidino[60]fullerenes C₆₀CH₂NMeCHX (X = C₆H₄N(CH₂CH₂Cl)₂, 2,6-(Bu^t)₂C₆H₂OH, PhC₆H₄, and indol-3-yl) was studied by ESR spectroscopy. The rate constants of R¹ radical addition to these compounds and dimerization of spin-adducts of the R¹ radicals with pyrrolidino[60]fullerenes were determined. Pyrrolidino[60]fullerenes manifest considerably higher reactivity toward the R¹ radicals than fullerene C₆₀ and methanofullerenes C₆₀CX¹X² (X¹ = X² = CO₂Et; X¹ = CO₂Me, X² = OP(OMe)₂, X¹ = X² = OP(OEt)₂).     

A procedure for preparing <Emphasis Type="Italic">N</Emphasis>-hydroxyethyl-substituted succinimide and phthalimide

Conditions of synthesis of N-hydroxyethyl-substituted succinimide and phthalimide by reactions of dicarboxylic acid imides with aminoethanol were optimized.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 12, 2004, pp. 2059–2060.Original Russian Text Copyright © 2004 by Gasanov, Allakhverdiev.     

Electrochemical Emission during Discontinuous Creep of Aluminum‒Magnesium Alloy

Crystallography Reports - It is experimentally established that the discontinuous creep of aluminum?magnesium alloy AlMg6, deformed in an aqueous medium, is accompanied by discrete...