Resonance electron capture by substituted cyclopropane molecules

Conclusions The fragmentation of substituted cyclopropanes under the conditions of dissociative electron capture is accompanied by the opening of the cyclopropane ring and is determined by the nature of the functional group. The increase in the number of electron-acceptor substituents noticeably stabilizes the molecular negative ions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2473–2478, November, 1987.     

Synthesis and structural characterization of isomeric coumarino‐1,2‐oxaphosphole derivatives

The coumarino‐[3,4‐c]‐3H‐10‐methyl‐2‐oxo‐2‐phenyl‐1,2‐oxaphosphole was prepared by the addition of PhPCl₂ to 3‐acetylcoumarin in the presence of acetic anhydride. Its conversion to the isomeric coumarino‐[3,4‐c]‐9H‐9‐methyl‐2‐oxo‐2‐phenyl‐1,2‐oxaphosphole was studied in different reaction conditions. The structures of the two isomers were determined by X‐ray crystallography and by ab initio molecular orbital calculations.     

Adsorption of an amphipatic copolymer on a kidney dialysis membrane

We have studied the adsorption of a copolymer of acrylonitrile and methacrylate of nonaethyleneglycol on a kidney dialysis membrane, which contains mostly nitrile groups. The kinetics study reveals at first a rapid increase of the adsorbance, followed by slow variations suggesting rearrangements at the interface. The isotherms do not present a true plateau at high concentration. The high adsorbance observed at low pH or high salt concentration could be related to the ability of polyethyleneoxide to form a complex with cations.     

Novel synthesis of Planococcus citri pheromone

An effective method was proposed for synthesizing (+)-cis-1R-acetoxymethyl-3-isopropenyl-2,2-dimethylcyclobutane, a pheromone of the citrus mealybug, based on ozonolysis of verbenone that led in one step to the key synthon 1R,3S-3-acetyl-2,2-dimethylcyclobutanecarboxylic acid. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 179–180, March–April, 2006.     

Synthesis and ozonization of (+)-4α-(1-trimethylsilyloxyethen-1-yl)-2-carene

(+)-4-(1-Trimethylsilyloxyethen-1-yl)-2-carene was synthesized, and the products of its ozonization were identified.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1984–1987, October, 1995.     

Ionic liquid-catalyzed Diels-Alder reaction of levopimaric acid with quinones

Diels-Alder reactions of levopimaric acid with quinones are strongly accelerated in the presence of ionic liquids (imidazolium salts) as catalyst.     

Synthesis of aryl-containing terpenoids based on 1,4-dihydronaphthalene

Successive transformations including oxidation of 1,4-dihydronaphthalene into 1,2,3,4-tetrahydronaphthalen-2-one, Reformatskii reaction of the latter with methyl bromoacetate, ozonolysis of the Reformatsky reaction product, and Emmons olefination of the aldehyde group in methyl 3-oxo-5-(2-formylphenyl)pentanate thus formed gave analogs of highly active dienoate juvenoids having an aromatic ring in their molecules.     

Simulation of ion transport in layered cuprate La2SrCu2O6

Oxygen diffusion in layered cuprate La₂SrCu₂O₆ has been simulated by the molecular dynamics method in the temperature range of 300–2500 K. The lattice is found to transform at temperatures above 1550 K; this transformation is accompanied by a change in the pair correlation functions. The abrupt change in the oxygen diffusion coefficient in the range of 1500–1550 K may indicate the presence of a phase transition to the superionic state. The motion of oxygen anions could be traced at the microscopic level. It has been proven for the first time that the La₂SrCu₂O₆ crystal lattice allows, along with displacements of O1 ions within the CuO₂ layer, their migration from the crystallographic positions to the intermediate unoccupied O3 positions. The motion of O2 anions is also fairly complicated: they move not only in their layer over the O2 positions but they also jump to the neighboring layer to occupy the O1 positions. The oxygen diffusion coefficient in layered cuprate La₂SrCu₂O₆ exceeds that in cuprates with perovskite structure and structure of the K₂NiF₄ type (at the same temperatures), which indicates that this material has good prospects for electrodes with mixed ionic-electronic conductivity.