The Initial Stages of the Onset of a Corona Discharge in a Wet Oxide Layer During the Passage of a High Voltage Current

Russian Physics Journal - The physical and chemical processes occurring in non-metallic inorganic porous coatings during the passage of a high-voltage alternating sinusoidal current through the...     

Structural and Optical Properties of CdSe/TiO2 Heterostructures Produced by High-Voltage Pulse Method

Russian Physics Journal - The paper focuses on morphology, as well as structural and optical properties of CdSe/TiO2 heterostructures. The samples were produced by high-voltage pulse method and...     

Synthesis of steroid analogs of tubuloclustin,their cytotoxicity and effect on microtubules of A549 carcinoma cells

Synthesis of analogs of tubuloclustin (N-(7-adamant-2-yloxy-7-oxoheptanoyl)-N-deacetylcolchicine (1)) with the colchicine fragment replaced with 2-methoxyestradiol scaffold attached via phenolic hydroxy group was described. Esters 3a–c exhibit moderate cytotoxicity (EC₅₀ = 5–6 μmol L^–1) and exert a weak effect on the microtubule network in A549 human lung carcinoma cells similar to the clustering effect of tubuloclustin and its derivatives. Conjugates 6a–c and 7a–c with the phenolic ester bond are low stable and compounds 7a–c are inactive to the microtubules of A549 cells, while compounds 6a–c cause an unusual effect of curling of the microtubules.     

Synthesis of stable o-sulfonylbenzonitrile oxides

The use of the o-orienting effect of the sulfonyl group during metallation with BuLi made possible the synthesis of o-sulfonylbenzaldehydes. Oxidation of their oximes with hypochlorite gave o-sulfonylbenzonitrile oxides, stable at 20°C, which are compounds not obtained previously. They form normal 1,3-dipolar cycloaddition products with styrene, and on heating, they dimerize into furoxanes. o-Sulfonyl-bisbenzonitrile oxide cyclizes into dibenzo[b,f]furazano[3,4-d]thiepin 1(3),8,8-trioxide. 2- and 2,2-Bistrimethylsilyldiphenyl sulfones were also synthesized, and their metallation was investigated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2081–2090, September, 1989.     

ESR spectra of copper compounds of α-thiopicoline anilides

ESR spectra are reported for numerous chelates with a Cu-2(N, S) center; the covalent Cu-N bond is found to produce additional hyperfine splitting in solutions and glasses. MOLCAO methods are applied for D_2h symmetry to estimate the degree of covalency of the bonds to N and S, and also the effective degree of covalency of the bonds. Substituents in the pyridine ring do not affect the covalency of the bonds, but they probably affect the covalency of the out-of-plane bonds from the copper to the addends. The steric hindrance produced by the substituents sometimes leads to reduction of the copper, as does the chelation. Substituents in the benzene ring do not affect the copper-addend bonds but do determine the molecular packing.The triaxial anisotropy of the g factor is discussed in relation to details of the crystal structure, including lack of equivalence of the Cu-N and Cu-S bonds.     

Reactions of 5-aminopyrimidines with phosphorus pentachloride

5-Amino-4, 6-dichloro-, 5-amino-4-chloro-6-methoxy-, and 5-amino-4-chloro-6-morpholinopyrimidines react with PCl₅ to form monomeric 5-(trichlorophosphoranyleneamino)pyrimidines.     

Heterocycles containing nitrogen and sulfur. Part 49. Synthesis of derivatives of new heterocyclic systems: 1,2-Dioxocyclopenta(hexa)[g]oxazolidino-[3,2-f] pyrimido[4,5-b][1,4]thiazine, 1,2-dioxocyclopenta(hexa)-[g] imidazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazine, and 1,2-oxazino[5,4-g]pyrimidino[4,5-b][1,4]thiazine

The reaction of 4-methoxy-5-amino-6-mercaptopyrimidine with 2-oxo-1-chlorocyclopentyl(hexyl)glyoxalate esters gave derivatives of the previously unknown tetracyclic systems 1,2-dioxocyclopenta (hexa)[g]oxazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazines, which are transformed by ammonium acetate into derivatives of 1,2-dioxocyclopenta(hexa) [g]imidazolidino[3,2-f]pyrimido[4,5-b]-[1,4] thiazines. Derivatives of the new tricyclic 1-oxazino [5,4-g]pyrimido[4,5-b][1,4]thiazine system were obrtained by reaction of 6-carbethoxy-7-acetylpyrimido [4,5-b] [1,4] thiazines with hydroxylamine.     

Heterogeneous Metal Oxide Coatings with Magnetoactive Nickel,Cobalt, and Iron Phases Formed by the Method of Pulsed Microplasma Oxidation for Radiation Absorption in the Middle and Near-IR Regions

Russian Physics Journal - Heterogeneous coatings with high ability to absorb electromagnetic radiation in the middle (4000–400 cm–1) and near-IR regions (11000–2000 cm–1)...