Forty years after the discovery of metallocene catalysts, there are still several aspects that remain unresolved, especially when “conventional” alkylaluminum activators not used. Herein, we systematically investigated synthesis polyethylene (PE) via three different zirconocene with alkyl substituents, activated organoboron compounds. The polymerization behavior, as well properties materials, w...

The title compound, C(24)H(34)O(6)·2C(3)H(7)NO, which was isolated from fumaric-modified rosin, has four asymmetrically fused six-membered rings and three carboxylic acid substituents. It contains two fused and unbridged cyclo-hexane rings, which form a trans ring junction with a chair conformation. The asymmetric unit includes one fumaropimaric acid and two dimethyl-formamide mol-ecules. The c...

The first examples of halogen bonding redox-active ferrocene receptors and their anion electrochemical sensing properties are reported. Halogen bonding was found to significantly amplify the magnitude of the receptor's metallocene redox-couple's voltammetric responses for halide sensing compared to their hydrogen bonding analogues in both acetonitrile and aqueous-acetonitrile solvent media.

Alkali metal complexes of two types of ansa-tris(allyl) ligand are reported; a monoanionic ansa-tris(allyl) ligand containing tin(II) is formally valence isoelectronic to the cyclopentadienyl ligand and a trianionic ansa-tris(allyl) ligand containing silicon(IV) is formally valence isoelectronic to an ansa-metallocene ligand; the potential wider use of these tripodal ligands in coordination che...

A novel non-metallocene titanium complex was synthesized, and used as the catalyst for ethylene polymerization. It results in an acceptable activity, affording the polyethylene with ultra high molecular weights, and relative broad molecular weight distributions. Moreover, the molecular weight almost doesn’t change with the change of Al/Ti ratio.

bis(indenyl)zirconium dichloride as a catalyst was synthesized using a modified method at the room temperature. polymerization of ethylene and copolymerization of ethylene and propylene were carried out by this metallocene catalyst. ethylene propylene (p/e) feed ratios of 0.25, 0.5, 1, and 2 were employed into the copolymerization systems. copolymerization conditions like cocatalyst/catalyst ra...

in this research different types of al2o3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. these supports were al2o3 from merck, axen and gamma al2o3 synthesized from al(oh)3. sn/pt/al2o3 catalysts were prepared by sequential impregnation, at first pt and then sn was deposited. characterization of catalysts was performed by x-ray powder diffraction (xrd)...