Complex formation of dimeric cyclophane zinc diphenylporphyrinates with 1,4-diazabicyclo[2,2,2]octane and pyrazine

The formation of host-guest complexes between dimeric cyclophane zinc diphenylporphyrinates and bidentate ligands of different nature containing two nitrogen atoms has been studied by the spectrophotometric titration method and ¹H NMR spectroscopy in a toluene-methanol (2: 1) binary solvent. The complexation of these dimeric porphyrinates with 1,4-diazabicyclo[2,2,2]octane or pyrazine can lead to 1: 1 or 1: 2 complexes, depending on the metalloporphyrin-to-ligand molar ratio. The stability constants of the porphyrinate-ligand complexes and concentration ranges of their formation have been determined.     

Thermodynamic properties of ferrites of composition GdMIIFe2O5.5 (MII = Mg, Ca, Sr)

Ferrites with the composition GdM^IIFe₂O_5.5 (M^II = Mg, Ca, Sr) were synthesized from the corresponding oxides by the solid-phase method. The temperature dependence of the specific heat was studied by dynamic calorimetry in the temperature range 298.15 673 K. Equations describing this temperature dependence were derived. The temperature dependences of the thermodynamic functions were calculated.     

Investigation of the character of the exchange interaction in the system Hg1−xMnxSe

A new method is proposed for determining the magnetic characteristics (magnitude and sign of the exchange interaction energy and the average size of clusters of magnetic ions) of dilute solid solutions of semimagnetic semiconductors at low temperatures based on oscillation measurements. The method makes it possible to find the magnetic characteristics of the indicated systems at temperatures between the point of the transition into the spin glass state and the temperature corresponding to the characteristic binding energy of magnetic atoms in clusters, for which standard methods based on the measurement of the magnetic susceptibility are not effective. The method is used to study the character of the exchange interaction in the system of solid solutions Hg_1–xMn_xSe as a function of their composition as well as under conditions of hydrostatic compression. To this end the oscillations of the magnetoresistance (Shubnikov-de Haas (SH) effect) in single-crystalline samples of Hg_1–xMn_xSe in the region of compositions 0.001 x 0.23 in magnetic fields H up to 65 kOe at temperatures T = (0.4–20) K and pressures up to 16 kbar were studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 29–39, November, 1989.     

Study on analysis of153Sm-EDTMP stability in vitro and vivo by HPLC

The behavior of¹⁵³Sm-EDTMP in vitro and vivo is analyzed by the size exclusion HPLC. The experimental results show that EDTMP amounts have an obvious effect on the stability in vitro and uptake of¹⁵³Sm-EDTMP in the liver. HPLC analysis of urine sample indicates that¹⁵³Sm-EDTMP es excreted in the original form. The behavior in vivo of¹⁵³Sm-EDTMP containing 4 μg is similar to that of¹⁵³Sm-EDTMP containing 50 μg EDTMP at 1 h post-injection.     

Complexes of pyridinium cyclopentadienylide with chromium and molybdenum carbonyls

Conclusions The pyridinium cyclopentadienylidechromium(molybdenum) tricarbonyl complexes were synthesized and a study was made of their IR, NMR, and mass spectra.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 227–228, January, 1977.The authors express their gratitude to N. I. Vasyukova and G. A. Panosyan for taking the mass and NMR spectra.     

Dehydrogenation of 1-(diphenylphosphinoyl)-2-(N′-phenylhydrazino)ethane and N-butyl-N′-phenylhydrazine

Dehydrogenation of 1-(diphenylphosphinoyl)-2-hydrazino-substituted ethanes and N-butyl-N′-phenylhydrazine to the corresponding hydrazone derivatives is performed. Both reactions were established to involve predominantly, if not exclusively, an azo intermediate.     

Crystal Structure of Ternary Molybdate Rb5FeHf(MoO4)6 — a New Phase in the Rb2MoO4-Fe2(MoO4)3-Hf(MoO4)2 System

Physicochemical analysis (XRPA, DTA) was used to study phase equilibria in a ternary salt system Rb₂MoO₄-Fe₂(MoO₄)₃-Hf(MoO₄)₂ in the subsolidus region. Ternary molybdates with compositions 5:1:3, 5:1:2, and 1:1:1 have been found and synthesized. Crystal and thermal characteristics have been determined. Single crystals of the ternary molybdate Rb₅FeHf(MoO₄)₆ with a composition of 5:1:2 were grown. The crystal structure of the compound was solved using X-ray diffractometry (CAD-4 automatic diffractometer, MoK _α radiation, 1766 F(hkl), R = 0.0298). Hexagonal crystals with unit cell dimensions: a = b = 10.124(1) Å, c =15.135(3) Å, V = 1343.4(4) ų, Z = 2, ρ_calc = 4.008 g/cm³, space group P6₃. The mixed three-dimensional framework of the structure is formed from two sorts of MoO₄ tetrahedra and Fe and Hf octahedra linked through their common O-vertices. Rubidium atoms of three varieties occupy the large voids of the framework.Original Russian Text Copyright © 2004 by B. G. Bazarov, R. F. Klevtsova, A. D. Tsyrendorzhieva, L. A. Glinaskaya, and Zh. G. Bazarova__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1038–1043, November–December, 2004.     

Micellar effects of surfactants in cleavage of 4-nitro-phenyl diethyl phosphonate by hydroperoxide anion

We have studied the nucleophilicity of the hydroperoxide anion relative to 4-nitrophenyl diethyl phosphonate (NPDEPS) in the presence of cetyltrimethylammonium bromide (water, 25 °C) while varying the acidity of the medium and the hydroperoxide anion concentration over a broad range. The increase in the reaction rate when the reaction is transferred to a micellar pseudophase is as high as ∼10-fold, which is explained by concentration effects. In CTAB micelles, as in water, the hydroperoxide ion is one of the most effective α-nucleophiles, and the size of the α-effect, characterized by the ratio of the second-order rate constants for reactions of HOO⁻ and OH⁻ anions with NPDEPS, remains practically constant and reaches a value of ∼50-fold. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 357–363, November–December, 2006.     

Comparison of Carboxamides Reactivity with Respect to Benzoyl Chloride and Diphenyl Chlorophosphate in Acetonitrile

For amides belonging to series RCONH₂ (I), RCONHMe (II), RCONHPh (III), and RCONMe₂ (IV) rate constants k₁ (l mol^-1 s^-1) were determined (in acetonitrile at 25°C) specifying the nucleophilic reactivity of the oxygen atom in amides toward benzoyl chloride and diphenyl chlorophosphate. The lack of substrate selectivity in the reactions in question was established. For equal values of inductive constants ^* of the R substituents the reactivity sequence of amides with respect to both substrates is the same (I >> IV > II, and III > II), and it does not follow the corresponding sequence of basicities. A conclusion was drawn that both groups of reactions proceed through cyclic transition states resembling reagents: six-membered with amides I and III, and five-membered with amides II and IV.     

Sulfenyl halides in the synthesis of heterocycles. 3. Interaction of perfluoro-1-ethyl-2-methyl-1-propenyl-iminochloromethanesulfenyl chloride with 1-allyl-2-methoxybenzene

Reaction of perfluoro-1-ethyl-2-methyl-1-propenyliminochloromethanesulfenyl chloride with 1-allyl-2-methoxybenzene in methylene chloride and nitromethane gives as the main products β-and β-chloro sulfides plus derivative of 2,3-dihydrobenzofuran. The reaction in nitromethane in the presence of lithium perchlorate gave a product of addition of sulfur-containing electrophiles to the double bond-a derivative of 1,3-thiazolidin-2-one-in preference to the cycloaddition product. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1558–1564, October, 2006.