Study of the products of the dehydration reaction of CuSO4 · 5H2O in X-shaped and elliptic nuclei

The products of the dehydration of CuSO₄ · 5H₂O under different conditions have been studied by the methods of local X-ray diffraction analysis and EPR. It is shown that the dehydration in vacuo when X-shaped nuclei are formed proceeds through the formation of an intermediate product having a monohydrate composition and a crystalline lattice close to the initial lattice of the pentahydrate. Then the amorphization and crystallization of CuSO₄ · H₂O follows. When dehydration occurs in water vapour through ellipsoidal nuclei the structure of the trihydrate formed is oriented relative to the initial structure of CuSO₄ · 5H₂O.     

Toward synthetic tubes for NO2/N2O4: design, synthesis, and host-guest chemistry

Design of molecular nanotubes is proposed for entrapment and conversion of NO2/N2O4 gases. Synthesis of 1,3-alternate bis-calix[4]arene tube 3 of 5 x 11 A internal dimensions is presented, and its reversible reactions with NO2/N2O4 in solution are studied. Exposure of 3 to NO2/N2O4 in chlorinated solvents results in the rapid encapsulation of nitrosonium (NO+) cations within its interior. Mono- and dinitrosonium complexes 4 and 5, respectively, were isolated and characterized by UV-vis, FTIR, and 1H NMR spectroscopies, and also molecular modeling. The NO+ entrapment process is reversible, and addition of water quickly recovered starting tube 3. Encapsulated within the tube NO+ species act as nitrosating agents for secondary amides. These findings open wider perspectives toward NO2/NOx storing and converting materials and also offer a promise for further development of supramolecular chemistry of synthetic nanotubes.     

Synthesis of 8-Aryl[1,2,4]triazolo[1,5-d][1,2,4]triazin-5(6H)-ones by S HN Reactions

A new procedure has been proposed for the synthesis of 8-aryl[1,2,4]triazolo[1,5-d][1,2,4]-triazin-5(6H)-ones by reaction of 6-aryl-1,2,4-triazin-3(2H)-ones with hydrazides derived from aliphatic, aromatic, and heterocyclic carboxylic acids. The process invloves nucleophilic substitution of hydrogen (S_N ^H)in aryltriazinones, oxidative closure of azole ring, and Dimroth rearrangement.     

Laser therapy of cancer patients

The results of using low-intensity copper-vapor laser radiation for patients already treated by conventional methods to prevent threatening postoperative and radiative complications are presented. The principal feasibility of using a copper vapor laser for treating precancer diseases is analyzed in a model of pretumor pathology of the stomach. Scientific Research Institute of Oncology of the Tomsk Scientific Center of the Russian Academy of Medical Sciences; Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 109–118, August, 1999.     

Toroidal Configuration of a Cholesteric Liquid Crystal in Droplets with Homeotropic Anchoring

JETP Letters - Orientational structures formed in cholesteric droplets with homeotropic surface anchoring have been studied by means of polarization optical microscopy and computer simulations. It...     

An efficient and green approach: One pot,multi component,reusable catalyzed synthesis of pyranopyrazoles and investigation of biological assays

An ecofriendly itinerary for the synthesis of pyranopyrazole derivatives having thioether link has been established via reusable, green catalyst, green solvent and multicomponent domino approach. To avoid impurities, usage of toxic solvents, toxic catalyst, simple workup and quantitative yields were strategies of this method. In addition, all the reported compounds were tested for their antioxidant and antibacterial properties. Some compounds displayed higher antioxidant activity than the standard drug (6a and 6j), while some other active compounds showed prominent antibacterial activity (6e and 6n). The results demonstrated that these active compounds may be used to support as a decent stand for further investigation in a way to ascertain innovative antioxidant and antibacterial medicines.     

Structure and thermal behavior of metastable sillenites prepared by mechanochemical synthesis

The structure and thermal behavior of metastable solid solutions with nominal compositions Bi₂PbO₄, Bi₄HgO₇, Bi₁₂TlO_19.5, and Bi₁₂Cd_0.7O_18.7 with the sillenite structure obtained by mechanochemical treatment in a planetary mill (thermal decomposition of the metastable Bi₄CdO₇ phase with a bcc structure above 700 K) have been studied. The large Pb²⁺ atoms occupy up to ~30% positions in the sillenite structure (Hg²⁺ and Hg(1) occupy up to ~15% of (24f) positions). The (2a) sites are partially occupied by bismuth with a minor shift along the [111] axis and are transformed into the (8c) site, forming an umbrella structure with c.n. 3. The relatively small Cd²⁺and Tl³⁺ cations partially occupy the (2a) sites. During annealing, the metastable Pb-sillenites are partially stabilized with a loss of oxygen and increasing content of bismuth. Sillenite with a high content of lead retains its structure until it melts at 923 K. Cadmium sillenite reacts with CdO, passing into a rhombohedral structure at 900 K (30 K below the melting point). Mercury sillenite Bi₄HgO₇ decomposes with isolation of metallic mercury at ~600 K.Original Russian Text Copyright © 2004 by V. V. ZyryanovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 480–490, May–June 2004.     

Orientational structure transformations caused by the electric-field-induced ionic modification of the interface in nematic droplets

The films of a polymer-dispersed nematic liquid crystal doped with an ionic surfactant were studied. The surface-anchoring modification effect caused by the local increase in the concentration of surface-active ions was observed at the polymer-liquid crystal interface under the action of an electric field. The modification of the boundary conditions leads to the transformation of the orientational structure of the nematic droplets and, as a result, to an appreciable change in their texture patterns and light-scattering efficiency at the interfaces. The monopolar director configurations (normal and curved) arising in the process of orientational structure transformations are considered and their typical textures are demonstrated. The possibility that the monopolar structure can be formed is theoretically substantiated by the computer simulation of the director field in a nematic droplet with the boundary conditions corresponding to the experiment.     

Synthesis of Novel 3-(Pyridin-4-yl)-1,2,4-Triazines,their Analogs and Study of the Activity Against Vaccinia Virus

Chemistry of Heterocyclic Compounds - Using atom-economical approaches, new representatives of 3-(pyridin-4-yl)-1,2,4-triazines and their 4-nitrophenyl analogs were obtained, and their activity in...