4419-47-0Relevant articles and documents
Synthesis, characterization and catalytic activity of the complex titanium bis(dimethylmalonate)-bis(diethylamido) in the polymerization of propylene
Gueta-Neyroud, Tal,Tumanskii, Boris,Botoshansky, Mark,Eisen, Moris S.
, p. 927 - 939 (2007)
In this account we present the synthesis, characterization and catalytic activity in the polymerization of propylene of a bis(dimethyl malonate) titanium bis(diethylamine) complex (1). The complex exhibits in solution a dynamical isomerization following an internal Bailar twist. The activation of complex 1 was obtained by its reaction with methylalumoxane (MAO). The activated complex in solution shows a different dynamic process involving an equilibrium between a monodentate η1 and bidentate η2 binding of the dimethylmalonate ligand to the metal center. This equilibrium is responsible for the formation of, at least, two active species for the polymerization reaction bearing major symmetry differences. The monodentate coordination (opened form) of the ligand was found to be the major form of the active species of the complex when activated with MAO, most probably due to a strong interaction of the oxygen atoms in the ligand with the strong Lewis acid co-catalyst. The active species in the polymerization were studied by NMR and ESR spectroscopies. The resulting polypropylene showed elastomeric properties with low tacticites.
PROCESSES FOR PRODUCING TRANSITION METAL AMIDO AND IMIDO COMPOUNDS
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Page/Page column 7-8, (2009/10/21)
Processes are provided for producing transition metal amidos and/or imidos. In methods according to this invention, at least one halogenated transition metal, an amine compound and a solvent are combined, followed by the addition of an alkylated metal or a Grignard reagent to produce the transition metal amide and/or imido.
Dihydrocarbylamino metal compounds
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Page/Page column 8-12, (2008/06/13)
This invention provides a process of preparing dihydrocarbylamido metal compounds. This process comprises bringing together, in a liquid reaction medium, at least one metal halide, MX4, where M is titanium, zirconium, or hafnium, and X is a halogen atom, with at least one dihydrocarbylamine, such that a mixture of (i) halometal amides in which the atom ratio of halogen to metal is greater than about 0.1 and less than about 2, and (ii) dihydrocarbylamine hydrohalide is produced. Then (i) and (ii) are separated from each other, and (i) is brought together with an alkali metal amide, ANR2, where A is an alkali metal, and R is a hydrocarbyl group, in a liquid medium, to produce a product comprised of substantially halogen-free dihydrocarbylamido metal compound. This invention further provides for purifying dihydrocarbylamido metal compounds by contact with a nitrile.
