Synthesis and properties of tetraalkylammonium chlorides peroxosolvates (CH3)4NCI·H2O2 and (C2H5)4NCl·H2O2

Tetraalkylammonium chlorides peroxosolvates (CH₃)₄NCl·H₂O₂ and (C₂H₅)₄NCl·H₂O₂ were synthesized. The composition of the solvates was proved by chemical analysis; their X-ray patterns, IR spectra, and thermograms were obtained. The solubility of the solvates in water and their stability in aqueous solutions were investigated.     

Dislocations in magnetic garnet crystals

1. Dislocations in magnetic flux-grown garnet crystals (Y₃Fe₅O₁₂ and others) have been observed. As a rule, {110} growth pyramids have more defects than {211} ones. 2. The highest content of defects (dislocation density 10³–10⁴ cm⁻²) is observed in Y₃Fe₅O₁₂ that grows on crucible walls adjacent to the free surface of the solution where the flow of heat is not uniform to the greatest degree. Bottom grown crystals usually have less dislocations. Far fewer dislocations are in wall grown crystals, least of all dislocations are contained in crystals that grow inside the solution. The solution pouring off at the end of the crystallization period increases dislocation density by some dozens. 3. Heat treatment decreases dislocation density. The less dislocation content and the lower ordering are in the initial crystal, the higher heat treatment effectiveness.     

The reaction of selenium with phenylacetylene

The reaction of selenium with phenylacetylene in the presence of sodium ethoxide in boiling dioxane has given 2, 5-diphenyl-1, 4-diselenacyclohexa-2, 5-diene, whose molecules have the boat conformation.     

Multicomponent reactions in the synthesis of dihydropyrimidine-containing podands having tuberculostatic activity

Dihydropyrimidinethione podands, as well as podands containing 2-thienyl substituents have been synthesized via the multicomponent Biginelli reaction. Tuberculostatic activity of the novel podands was shown to depend on the polyether unit length. In particular, activity of dihydropyrimidinethione podands against laboratory strains of Mycobacterium tuberculosis, H₃₇Rv, M. avium, M. terrae, and the clinical strain of multi-drug resistant M. tuberculosis (MDR), increases with a shortening of the polyether unit length.     

Synthesis of esters of iminocarbonic acid

The first syntheses of asymmetrical esters of iminocarbonic acid are reported. These syntheses were carried out without the separation of intermediates. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, p. 23, October, 1989.     

4-Hydroxyproline containing podands as new chiralcatalysts for the asymmetric Biginelli reaction

The novel C₂-symmetric chiral organocatalysts of (2S,4R)-hydroxyproline containing podand type have been synthesized and evaluated in the asymmetric Biginelli reaction. Combination of polyether spacer with (2S,4R)-hydroxyproline allowed one to enhance the effect of the latter on enantioselectivity of the Biginelli reaction by a factor of 5. The best results have been achieved for salts of (2S,4R)-hydroxyproline containing podands with trifluoroacetic acid.

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Thermally initiated disproportionation of manganese(II) bis(1-hydroxyethylidene)diphosphonate. Formation and properties of the lepidoid structure of manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium whiskers. Agronomical efficiency of the manganese(II) complex with (1-hydroxyethylidene)diphosphonic acid

Russian Chemical Bulletin - The reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate (Mn(H3L)2?4H2O) with 2-aminoethanol (H2NCH2CH2OH) in an aqueous...