Coordinative chain transfer polymerization (CCTP) has opened a new path for the development of novel products like olefin block copolymers and chain-end functional polyolefins. However, conflicting results are frequently reported on the catalyst performance including activity and comonomer selectivity under CCTP conditions. Here we have selected two catalysts including rac-ethylenebis(1-η5-inde...

Reaction of (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline with [Cp*IrCl2]2 in benzonitrile with KPF6 and NaOH gave (η(5)-(S)-2-(4-(1-methylethyl))oxazolinylcyclopentadienyl)(η(5)-pentamethylcyclopentadienyl)iridium(iii) hexafluorophosphate (68%). This transformation of an iron-based into an iridium-based metallocene proceeds via the rearrangement, with loss of cyclopentadienyliron, of an intermed...

Dehydrogenation of Me(2)NH·BH(3) (1) by group 4 metallocene alkyne complexes of the type Cp(2)M(L)(η(2)-Me(3)SiC(2)SiMe(3)) [Cp = η(5)-cyclopentadienyl; M = Ti, no L (2Ti); M = Zr, L = pyridine (2Zr)] and group 4 metal amido complexes of the type M(NMe(2))(4) [M = Ti (8Ti), Zr (8Zr)] is presented.

The U(IV) linear pentacyano metallocene [U(C(5)Me(5))(2)(CN)(5)][NEt(4)](3) reacted with 2 molar equivalents of pyridine N-oxide in THF or acetonitrile to give the U(VI) complex [UO(2)(C(5)Me(5))(CN)(3)][NEt(4)](2), the first uranyl species containing the cyclopentadienyl ligand; the crystal structure revealed that the steric effects of the (C(5)Me(5)) ligand force the {UO(2)}2+ ion to deviate ...

Homogeneous surface coating of long carbon nanotubes is achieved by in situ polymerization of ethylene as catalyzed directly from the nanotube surface-treated by a highly active metallocene-based complex and allows for the break-up of the native nanotube bundles leading, upon further melt blending with HDPE, to high-performance polyolefinic nanocomposites.

The constrained density functional theory (CDFT) was used to study bridge-mediated electron transfer processes in mixed-valence systems with two identical metallocene (cobaltocene, ruthenocene, and nickelocene) moieties linked by various bridge structures. Based on the electronic coupling matrix elements obtained from the CDFT calculations, the relationship between the bridge linkage and the e®...

Microwave irradiation can be used to heat conductive materials and metallocene precursors to initiate ultrafast CNT growth. It takes only 15-30 seconds to grow CNTs at room temperature in air, without the need for any inert gas protection and additional feed stock gases.

Linear low-density polyethylene (LLDPE) materials may contain components, which are soluble at room temperature. These influence physical properties or raise concerns for end-users and regulatory bodies because LLDPE is widely used food packaging. Due to the nonpolar amorphous nature of temperature part LLDPE, its molecular characterization with common methods polyolefin analysis, such as Tempe...

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...