Isospecific Propylene Polymerization Behavior of Lewis Base Functionalized Unbridged Zirconocences under Bulk Conditions

Endowing aspecific, unbridged-metallocene propylene-polymerization catalysts with isospecificity: the unprecedented role of MAO.

Polymerization of propylene in a minireactor: Effect of polymerization conditions on particle morphology

Gas phase polymerization of propylene was carried out in a semi-batch minireactor using a commercially supported Ziegler–Natta (ZN) catalyst. The influence of variables including monomer partial pressure, external electron donor, reaction temperature and time on the particle morphology and size distribution was investigated. Generally, more uniform fragmentation and particle densities were obta...

Zirconium and hafnium Salalen complexes in isospecific polymerisation of propylene.

The activity of dibenzylzirconium and dibenzylhafnium Salalen complexes in polymerisation of propylene with MAO as a cocatalyst is described. Three Salalen ligand precursors combining a bulky alkyl group (1-adamantyl) on the imine-side phenol and electron withdrawing halo groups of different sizes on the amine-side phenol were explored. All metal complexes were obtained as single diastereomers....

Lewis pair polymerization by classical and frustrated Lewis pairs: acid, base and monomer scope and polymerization mechanism.

Classical and frustrated Lewis pairs (LPs) of the strong Lewis acid (LA) Al(C(6)F(5))(3) with several Lewis base (LB) classes have been found to exhibit exceptional activity in the Lewis pair polymerization (LPP) of conjugated polar alkenes such as methyl methacrylate (MMA) as well as renewable α-methylene-γ-butyrolactone (MBL) and γ-methyl-α-methylene-γ-butyrolactone (γ-MMBL), leading to high ...

Lewis acid-catalyzed, copper(II)-mediated synthesis of heteroaryl thioethers under base-free conditions.

A Lewis acid (Ag(I), Ni(II), or Fe(II)) catalyzed, Cu(II)-mediated thiolation reaction between heteroarenes and thiols was achieved with good yield under base-free conditions. DMSO could serve as an effective methylthiolation reagent for the synthesis of heterocyclic methyl thioethers.