Vyatcheslav V. Izmer

Titanium and zirconium complexes with η5: η1-4-(alkyl/arylamino)(dimethyl)silylindene ligands as catalysts for ethene polymerization

First members of a novel family of constrained geometry complexes of titanium and zirconium containing a short bridge between the amide and inden-4-yl fragments were obtained. When activated with methylaluminoxane, these complexes can be used as highly active catalysts for ethene polymerization producing high-molecular-weight polymers.

Synthesis and structural study of 3-phenyl-6,7,8,9-tetrahydrocyclopenta[ a ]naphthalene-containing ansa -complexes of zirconium

The zirconium rac- and meso-complexes of the ansa-type that contain a 3-phenyl-6,7,8,9-tetrahydrocyclopenta[a]naphthalene fragment and a dimethylsilylene bridge are synthesized. The compounds obtained are characterized by NMR spectroscopy; the structure of rac-complex is studied by X-ray diffraction, which maked it possible to evaluate the steric availability of the zirconium center in the corresponding catalysts for the olefin polymerization.

Coupling of aromatic aldehydes with aryl halides in the presence of nickel catalysts with diazabutadiene ligands

Nickel catalysts with diazabutadiene ligands promote cross-coupling of benzaldehydes with aryl halides in the presence of zinc as reducing agent, which leads to the corresponding benzhydrols and benzophenones. The benzophenone percentage considerably increases when lithium chloride additive is used.

Crystal structures of di-μ-bromido-bis{di­bromido­[η5-2-(di­methyl­amino)­inden­yl]zirconium(IV)} and di­bromido­bis­[η5-2-(di­methyl­amino)­inden­yl]zirconium(IV)

Molecules of di[(μ-bromido)(η5-2-dimethylaminoindenyl)dibromidozirconium(IV)], (I), and bis(η5-2-dimethylaminoindenyl)dibromidozirconium(IV), (II), are dinuclear with one CP ligand and four Br ligands for each of the ZrIV atoms and mononuclear with two CP and two Br ligands for the ZrIV atom, respectively.

Zirconium complexes of cyclopenta[b]pyridine: synthesis, structure, and olefin polymerization catalysis

By treatment of Cp*ZrCl3 with the lithium salt of cyclopenta[b]pyridine (LiCpPy) in toluene, the unsymmetrical complex Cp*(η5-CpPy)ZrCl2 was prepared in 32% yield. On the evidence of X-ray crystal structure analysis, the bifunctional CpPy ligand coordinates Zr in an η5-manner rather than via nitrogen. Cyclopenta[b]pyridine turned out to react with Zr(NMe2)4 in toluene to form mono-cyclopentadienyl complex (η5-CpPy)Zr(NMe2)3(Me2NH) in 70% yield. The polymerization of ethylene and the copolymerization of ethylene with 1-hexene or propene catalyzed by Cp*(η5-CpPy)ZrCl2 activated with MAO was studied in detail.