The first example of the stereoselective synthesis and crystal structure of a spirobicycloquinazolinone based on (–)‐fenchone and anthranilamide

The possibility of a single‐stage solvent‐free stereoselective synthesis of a spirocyclic compound from the natural bicyclic monoterpenoid (?)‐fenchone and anthranilamide has been shown for the first time. The molecular and crystal structure of (1R,2S,4S)‐1,3,3‐trimethyl‐1′H‐spiro[bicyclo[2.2.1]heptane‐2,2′‐quinazolin]‐4′(3′H)‐one, C₁₇H₂₂N₂O, was established by X‐ray diffraction though the chirality was assumed via the known reactant connectivity and ¹H and ¹³C NMR spectroscopy. It has shown that in the molecule, for steric reasons, there is an elongation of the Me₂C—C(N)N bond to 1.603 (5) Å. The formation of dimers via N—H…O=C hydrogen bonds with an interaction energy of 93.30 kJ mol^?1 and through cavities (33.7% of the unit‐cell volume) was established in the packing of the molecules. There are no π‐stacking interactions in the structure.     

Superparamagnetic properties of anisotropic particles

We consider the effect of the magnetic anisotropy of superparamagnetic particles on the magnetization process. We check calculations of the temperature dependence of the magnetization in two limiting cases: the particles are rigidly attached to a nonmagnetic matrix, or the particles are free, leading to rotational degrees of freedom. We estimate the magnetocaloric effect in these systems.Krasnoyarskii University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 110–114, July, 1995.     

Synthesis and Some Colloidal Properties of Hydrosols Prepared by the Hydrolysis of Copper(II) Nitrate

The synthesis of hydrosols of copper(II) basic salts by the hydrolysis of copper(II) nitrate in the presence of ammonia was developed. A pH range and an optimal molar ratio [Cu²⁺] : [OH^–] = 1.1 : 1.0, at which hydrosols stable with respect to sedimentation were formed, were determined. The average hydrodynamic radius of dispersed phase particles ranging from 220 to 280 nm was measured by the photon correlation spectroscopy. It was shown that the hydrosols can be stabilized by poly(vinyl alcohol), and its optimal concentration providing their aggregation stability was determined. The thresholds of fast coagulation of the initial and stabilized hydrosols in the presence of potassium chloride and ammonium sulfate were found.     

Oxide layers with titanium and zirconium phosphates

Oxide-phosphate layers 20 to 150 μm thick were obtained on titanium by plasma electrolytic deposition in individual and mixed aqueous electrolytes with polyphosphate complexes of zirconium(IV), barium(II), and copper(II). Formation features, thickness, elemental and phase compositions, and surface morphology of the films are presented. Depending on the electrolyte composition, synthesis conditions, and temperature of annealing in air, some simple and double phosphates of titanium and zirconium are formed, including ZrP₂O₇, NaTi₂(PO₄)₃, BaTi₂(P₂O₇)₂, Zr_0.2Ti_0.8P₂O₇, and CuTi₂(PO₄)₃.     

The plasma-electrolytic formation of cerium-containing surface structures on titanium and aluminum

The possibility of obtaining cerium-containing structures on aluminum and titanium by the plasma-electrolytic method with the use of aqueous solutions of electrolytes containing Ce³⁺ polyphosphate complexes was demonstrated. The amount of cerium in the films obtained depended on the molar ratio n = [polyphosphate]/[Ce³⁺] in the electrolyte. The films contained crystalline CePO₄. The growth of films on titanium was characterized by the formation of secondary layers by the mechanism involving the appearance of new phase nuclei followed by their expansion.     

Antiulcerogenic activity of borneol derivatives

Antiulcerogenic activity of borneol and its N-heterocyclic esters was investigated using indomethacin-induced gastric ulcer model. A considerable antiulcerogenic effect comparable to that shown by Omeprazole and Famotidine was found for two investigated compounds in the indomethacin-induced gastric ulcer model. Bornyl 2-piperazinoacetate, with a non-substituted piperazine moiety, showed maximum antiulcerogenic activity in the indomethacininduced gastric ulcer model and demonstrated a significant gastroprotective effect in the ethanol-induced gastric ulcer model comparable to the effect of Omeprazole.