Formation,Structure and Magnetic Properties of Polymer Matrix Nanocomposites Processed by Thermal Decomposition of the Fe(III)Co(II) Acrylate Complex

Structure and magnetic properties of polymer matrix nanocomposites, processed by pyrolysis of the Fe(III)Co(II) acrylate complex, were investigated. It was shown that thermal transformation of the complex studied consisted of three macrostages: dehydration, solid state polymerisation and decarboxylation of a metallopolymer form. The main products of the decomposition were nanoparticles stabilised by polymeric matrix. The crystalline phases, which were found in the fully processed material, were Fe₃O₄, CoFe₂O₄ and CoO. The mean crystallite size was 10nm. In the intermediate stages of the thermolysis iron was present in the forms of Fe^III (trivalent low – spin iron), Fe²⁺(divalent high – spin iron) and Fe₃O₄. The hysteresis loops measured at temperatures below 200K were opened and shifted towards negative field. The coercivity and remanence showed room temperature values of 0.18T and 15.5mT, respectively.     

Preparation and reactivity of metal-containing monomers

XPS and IR studies and elemental analysis of the polymerization product of Cu(II) acrylate suggest the partial reduction of Cu(II) during polymerization. A scheme of the polymer structure with metals of different valencies is suggested.For part 31 see Izv. Akad. Nauk, Ser. Khim., 1993, 1293 [Russ. Chem. Bull., 1993, 42, 1236 (Engl. Transl.)].Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1565–1568, September, 1993.     

Homogeneous catalytic systems for the oxidative functionalization of alkanes: design,oxidants, and mechanisms

Russian Chemical Bulletin - The best examples of catalysts and catalytic systems for the oxidative functionalization of alkanes and mechanisms of their action are considered. The prospects for...     

Preparation and reactivity of metal-containing monomers 53. Synthesis and stability of a cluster monomer (μ-H)Os3(μ-OCNMe2)(CO)9PPh2CH2CH=CH2 in solution

The stability of the complex (μ-H)Os₃(μ-OCNMe₂)(CO)₉PPh₂CH₂CH=CH₂ (1), which contains a free unsaturated functional group in the terminal ligand PPh₂CH₂CH=CH₂, with respect to isomerization, chelation of the ligand, and other transformations in solutions was examined. No transformations of complex1 were observed in the course of synthesis from (μ-H)Os₃(μ-OCNMe₂)(CO)₉NMe₃ or upon heating in solution. Complex1 as well as complexes (μ-H)Os₃(μ-OCNMe₂)(CO)₉PHPh₂ and (μ-H)Os₃(μ-OCNMe₂)(CO)₉PPh₃, which were formed as admixtures, were isolated in the solid state and identified by¹H,¹H-{³¹P}, and¹H-{¹H} NMR, IR, and Raman spectroscopy and mass spectrometry. For Part 52, see Ref. 1. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1455–1460, August, 2000.     

Hybrid polymer-immobilized palladium nanoparticles: Preparation and catalytic properties

A new approach to the synthesis of mixed-type immobilized catalysts was developed: the frontal polymerization of a metal-containing monomer in the presence of a highly dispersed mineral support. The synthesis of an acrylamide complex of Pd(II) nitrate on the surface of SiO₂, Al₂O₃, or C and its subsequent polymerization and reduction resulted in the formation of an organic-inorganic composite that included nanosized Pd particles stabilized by a polymer matrix and an inorganic support. The resulting hybrid nanocomposites are efficient and selective catalysts for the hydrogenation reactions of cyclohexene and alkene and acetylene alcohols.     

Development of studies devoted to design of polymer-immobilized catalysts

The state of the art in the field of designing metal-complex catalysts for olefin polymerization immobilized on polymer supports is analyzed. The types of polymers used for binding transition-metal compounds and organoaluminum components and the topochemistry of their distribution and transformations in the course of catalyzed reactions are considered. Polymer-immobilized bimetallic catalysts show promise in the catalysis of the polymerization process in which the key role of a macroligand is to unite active centers of various kinds. It has been shown that, in metallocene and postmetallocene catalysts, the same construction principles of immobilization are preserved as in the case of first-generation metal-complex catalysts. The possibility of isolating and studying active intermediates offered by the polymer support and the effect of immobilization on the molecular design of polymer systems are discussed.     

Immobilized Osmium Clusters in the Processes of Liquid-Phase Oxidation of Cycloxehene

The reaction of catalytic hydroxylation of olefins by organic hydroperoxides in the presence of osmium carbonyl clusters supported on polymer matrices is studied. The process occurs with the predominant formation of unsaturated alcohols. The oxidative coupling of olefins with the formation of nonconjugated dienes and in which the double bonds remain intact occurs in parallel. In the course of the reaction, changes in the chemical structures of the initial osmium clusters are not observed.     

Some properties of filled polyvinyl chloride

The effect of TiO₂, SiO₂, and carbon fillers on rigid, partly plasticized PVC has been investigated. Interaction in the polymer-filler system improves certain important properties — hardness, stiffness, wear resistance, etc., — the effect of the fillers being highly specific.M. V. Lomonosov Odessa Technological Institute. Translated from Mekhanika Polimerov, No. 1, pp 124–126, January–February, 1970.