Reactivity of metal-containing monomers

Thermal conversion of cobalt(II) maleate, CoC₄H₂O₄2H₂O, (1) at 340–370 °C was studied. The composition of the products of pyrolysis was determined. The major solid-phase product of decomposition consists of nano-sized particles of CoO (sizes vary within narrow limits) stabilized by the polymeric matrix. Thermal conversions of Co^II maleate involve dehydration, polymerization of dehydrated monomers, and decarboxylation of the resulting polymer.     

Preparation and reactivity of metal-containing monomers. 13. Complexes of transition metals with methacroylacetophenone

Syntheses are reported for a series of metal- chelate monomers derived from metha-croylacetophenone. IR, UV, and magnetochemical data indicate an octahedral configuration of the chelate unit. The metal- ligand bond in the complexes of transition metals with methacroylacetophenone is significantly covalent in nature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 451–453, February, 1990.     

Formation of metal-containing nanoparticles in polymer matrix. Computer simulation of clusterization kinetics during the solid-phase thermal decomposition of metal-containing precursors

The scheme of computer simulation of the dynamics of the formation of metal-containing clusters in a polymer matrix during the solid-phase thermolysis of corresponding precursors is developed. The kinetics of particle nucleation and growth is studied within the framework of the model of diffusion-limited aggregation by the combined marching and Monte Carlo methods. Polymer media with different structural organization such as isotropic (globular) and anisotropic (layered and fibrillar) media are considered. Deterministic algorithms of the model are the decomposition of reactive metal-containing groups of a polymer, solid-phase diffusion of particles, and cluster dissociation. The proposed scheme makes it possible to visualize the process of cluster formation.61st communication from Preparation and Reactivity of Metal-Containing Monomers series. For 60th communication see [1].Translated from Kolloidnyi Zhurnal, Vol. 67, No. 1, 2005, pp. 70–78. Original Russian Text Copyright © 2005 by A.S. Rozenberg, A.A. Rozenberg, Dzardimalieva, Pomogailo.     

Synthesis and reactivity of metal-containing monomers 64. Synthesis,structure, polymerization,and catalytic properties of the palladium and cobalt vinylporphyrin complexes

2-Vinylporphyrin and its complexes with Pd^II and Co^II were synthesized and characterized by NMR, IR, and mass spectra. The palladium vinylporphyrin complexes are efficient metal-containing monomers in radical copolymerization with styrene. Palladium(II) in an amount of up to 1 mol.% can thus be introduced into the polymers. The synthesized polymeric Pd complexes perform the photosynthesized activation of dioxygen to the lowest excited singlet state, which is an active oxidizing agent for anthracene producing the 1,4-addition products. The monomeric and macromolecular cobalt complexes are chain-transfer catalysts in radical styrene polymerization. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 152–158, January, 2007.     

Synthesis and reactivity of metal-containing monomers

Thermal transformations of Fe^III maleate, [Fe₃O(OOCCH=CHCOOH)₆]OH·3H₂O (1), in an autogenerated atmosphere and the change in the short-range surrounding of Fe atoms during thermolysis were studied. The thermal transformations of1 are accompanied by the following processes: dehydration with simultaneous rearrangement of the ligand environment and formation of maleic acid, and polymerization of the rearranged monomer and its decarboxylation at high temperatures. In the initial stage of decarboxylation, the destruction of the metal-carboxylate Fe₃O complex occurs followed by the formation of the Fe−Fe bond (r=0.246 nm). The oxidation of the Fe atoms is observed when the thermolysis duration increases. For Part 49, seeIzv. Akad. Nauk, Ser. Khim., 1998; 1145 [Russ. Chem. Bull., 1998,47, 1113 (Engl. Transl.)]. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1505–1510, August, 1998.     

Synthesis and reactivity of metal-containing monomers. Part 59. Preparation and polymerization transformations of vinyl and isopropenyl derivatives of hafnocene dichloride

Novel vinyl- and isopropenyl-substituted cyclopentadienyl complexes of hafnium(IV), [C₅H₄(CR=CH₂)]₂HfCl₂[R = H (5), CH₃ (6)], were prepared and characterized. The organometallic monomers obtained were shown to undergo radical or anionic homopolymerization. Copolymerization of these metallocenes with styrene was performed. The potential applications of the metal polymers in question were considered.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 242–246, January, 2005.     

Thermal polymerization of cobalt(II) and nickel(II) acrylates: Use of in situ dielectric measurements

In situ dielectric spectroscopy at frequencies ranging from 1 to 10⁵ Hz was used to study chemical transformations during the heating of cobalt(II) and nickel(II) acrylates from ?160 to +400°C. On the basis of analysis of the evolution of dielectric relaxation time spectra, processes that correspond to three macroscopic stages in different temperature intervals were distinguished: dehydration, solid-state thermal polymerization, and decarboxylation of metallopolymers. These processes lead to the formation of a polymer matrix that stabilizes nanosized metal or metal oxide phases. In the case of cobalt acrylate, the crosslinking step occurs in a temperature interval other than that of polymerization. It was found that electric conductivity varies over six orders of magnitude upon the formation of the nanosized metal phase.     

Synthesis and reactivity of metal-containing monomers

The reaction of Rh₆(CO)₁₅MeCN with allyldiphenylphosphine under mild conditions afforded the cluster-containing complex [Rh₆(CO)₁₄(μ,η²-PPh₂Ch₂CH=CH₂)]. Its molecular structure was characterized. The resulting complex is an octahedral Rh cluster with ten terminal and four μ₃-bridging CO ligands. The average Rh?Rh distance is 2.762(2) Å. The unsaturated ligand is additionally coordinated to the metal center (Rh(4)–C(232), 2.37(1) Å; and Rh(4)–C(233), 2.32(2) Å) to form a π-bond.     

Structural organization and thermal transformations of various Ni(II) complexes as precursors of polymer-metal nanocomposites

Peculiarities of thermal transformations of metal-containing monomers and polymers prepared by various synthetic routes are analyzed. It is shown that the thermal stability of metalcarboxylate groups is determined by the spatial organization of the nearest environment and the microstructure of polymer chains formed as a result of thermal transformations. Main paths of thermal transformations of studied compounds are considered. Qualitative and quantitative compositions of the gaseous and solid-phase products at the end of transformations and some properties of forming polymer-metal nanocomposites are studied.60th communication from Preparation and Reactivity of Metal-Containing Monomers series. For 59th communication see [1].Translated from Kolloidnyi Zhurnal, Vol. 67, No. 1, 2005, pp. 57–69. Original Russian Text Copyright © 2005 by Rozenberg, Dzardimalieva, Chukanov, Pomogailo.