Imbedding in the class eL

Conditions which must be satisfied by the modulus of continuity and smoothness of a functionf(x) L_p(0, 2) in order thatf(x) or (x) belong to the class e^L are obtained.Translated from Matematicheskie Zametki, Vol. 10, No. 1, pp. 17–24, July, 1971.     

Photofission of 238Pu, 240Pu, and 242Pu in the energy range 5–10 MeV

The cross sections for the photofission of plutonium isotopes ²³⁸Pu, ²⁴⁰Pu, and ²⁴²Pu in the energy range 5–10 MeV have been measured by using a beam of bremsstrahlung photons from the microtron installed at the Institute of Physics and Power Engineering (Obninsk). The energy regions below the fission barrier and above 6 MeV have been scanned with pitches of 0.05 and 0.1 MeV, respectively. In deriving the absolute cross section for ²³⁸Pu photofission, ²³⁸U photofission has been employed as a reference reaction. In measurements involving ²⁴⁰Pu and ²⁴²Pu nuclei, the neptunium isotope ²³⁷Np, which is characterized by a more regular dependence of the photofission cross section on excitation energy than ²³⁸U, has been chosen for the first time as a reference nucleus. The measured cross sections as functions of energy show resonance structures in the vicinity of the fission threshold that are consistent with those previously observed in the energy dependences of fissilities for corresponding direct reactions. The partial-wave cross sections for the J ^π K = 1^?0, 1^?1, and 2⁺0 photofission channels have been determined as functions of energy. At energies below some 5.5 MeV, the total cross section for photofission of each plutonium isotope being studied receives a significant contribution from quadrupole interaction. Within the one-dimensional model of a two-humped fission barrier, the parameters of the barriers for ²³⁸Pu, ²⁴⁰Pu, and ²⁴²Pu have been extracted from data and have then been compared with estimates based on previous measurements.     

Homophtalonitrile for Multicomponent Reactions: Syntheses and Optical Properties of o-Cyanophenyl- or Indol-3-yl-Substituted Chromeno[2,3-c]isoquinolin-5-Amines

Malononitrile is a useful reagent for multicomponent reactions with hundreds of methods developed. In this paper, we suggest α-(cyano)-o-tolunitrile (homophtalonitrile) to work as a vinylogous malononitrile. Thus, a organocatalytic pseudo-three-component reaction of homopthalonitrile (2 equiv) and o-hydroxybenzaldehyde, leading to the diastereoselective formation of 5-amino-12H-chromeno[2,3-c]isoquinolin-12-yl)(cyano)methyl)benzonitriles, was discovered. The possibility to employ other nucleophiles was demonstrated for indoles, and a sequential three-component reaction of homophtalonitrile, o-hydroxybenzaldehyde, and (aza)indole, giving 12-(1H-Indol-3-yl)-12H-chromeno[2,3-c]isoquinolin-5-amines, was developed. The photophysical properties of the synthesized compounds have been studied, revealing high fluorescence quantum yields (42–70 %) for indol-3-yl substituted 12H-chromeno[2,3-c]isoquinolin-5-amines and reversible fluorescence quenching under acidic conditions.     

[Tri(tert-butoxy)silyl]methylmagnesium chloride

A reaction of potassium tert-butoxide with chloromethyltrichlorosilane in THF leads to tri(tert-butoxy)chloromethylsilane. Upon reflux in THF, it reacted with magnesium with the formation of stable [tri(tert-butoxy)silyl]methylmagnesium chloride, whose structure was confirmed by ¹H, ¹³C, and ²⁹Si NMR spectroscopy. In the THF solution at 25 °C, [tri(tert-butoxy)silyl]methylmagnesium chloride exists in the equilibrium with bis{[tri(tert-butoxy)silyl]methyl}magnesium (in the ratio of 1: 1).     

Reaction of unsaturated nitriles with hydrosilanes

Reaction of acrylonitrile and 1,4-dicyanobut-1-ene with hydrosilanes in the presence of various catalysts was studied. In the presence of triallylamine, allyl-bis(triethoxypropyl)amine, diallylaminopropyltriethoxysilane, HMPA, NiCl₂ + 2MePh₂PO, CuCl + 2MePh₂PO, [(Me₂N)₂CCl]₂CuCl₄, and [(Me₂N)₂CCl]₂PtCl₆, the addition of trichlorosilane to acrylonitrile proceeded with the yield of 36 to 97%. Triethoxy- and tributoxysilane were added to acrylonitrile in the presence of rhodium dicarbonyl acetylacetonate with the formation of α-isomer in 56–58% yield. Attempted addition of hydrosilanes to 1,4-dicyanobutene failed.     

Chemical transformations of diazoles in the reactions with dimethylchloromethylchlorosilane

The behavior of 3,5-dimethylpyrazole, 3(5)-methylpyrazole, imidazole, and their trimethylsilyl derivatives in the reactions with dimethylchloromethylchlorosilane or its mixture with hexamethyldisilazane was studied. The processes are found to lead to the formation of the products of resilylation, which under the reaction conditions are isomerized into the silylmethylated products.     

New thermally conductive silicone adhesive sealants

Single-component silicone adhesive sealants of the Elasil range of the 137-182М, 137-182М1, 137-182М2, and 137-182М3 brands developed at the Scientific Research Institute of Chemistry and Technology of Organoelement Compounds are presented. It is demonstrated by the results of thermophysical tests that their coefficient of thermal conductivity is more than 1.5-fold higher than the coefficient of thermal conductivity of an Elasil 137-182 commercial single-component silicone adhesive sealant and they can be used in radioelectronic equipment to abstract heat generated from heat-loaded elements.     

Synthesis and structure of <Emphasis Type="Italic">N</Emphasis>-(2-silatranylethyl)pyrazoles

Organosilicon pyrazole derivatives containing a 2-siltranylethyl fragment on the nitrogen atom were synthesized, and their structural and stereoelectronic parameters were determined by X-ray analysis and ¹H, ¹³C, and ²⁹Si NMR spectroscopy. The nature of interaction between the pyrazole and silatrane fragments was studied.     

On the structure of luminol sodium salts

The structures of Tamerit® (A) and Galavit® (B) pharmaceutical preparations have been solved by X-Ray single crystal and powder diffraction. These are luminol sodium salts possessing immunomodulatory and anti-inflammatory properties. It is shown that Tamerit® (A) is a hydrated salt, while Galavit® (B) is a mixture of two polymorphic modifications (B1 and B2) of anhydrous salt. Compound A is crystallized in a monoclinic system: a = 8.3429(4) Å, b = 22.0562(11) Å, c = 5.2825(2) Å, β = 99.893(3)°, V = 957.59(8) ų, and Z = 4; sp. gr. P2₁/c. Compound B1 is crystallized in a monoclinic system: a = 14.7157(18), b = 3.7029(19), c = 16.0233(15) Å, β = 116.682(13)°, V = 780.1(4) ų, and Z = 4; sp. gr. P2₁/c. Compound B2 is crystallized in an orthorhombic system: a = 27.7765(15) Å, b = 3.3980(19) Å, c = 8.1692(19) Å, V = 771.0(5) ų, and Z = 4; sp. gr. Pna2₁. The absence of phase transitions between the B1 and B2 polymorphs has been established by differential scanning calorimetry.