Biaryl-bridged Schiff base complexes of zirconium alkyls: synthesis structure and stability

Expression of chirality in salicyloxazolinate complexes of zirconium

“…The remaining mutually trans sites are occupied by the aryl oxygens at a O-Zr-O bond angle of 167.1(3). These and other metrical parameters are comparable to related Schiff base [19,20] and oxazoline [14] complexes.…”

A Binaphthyl‐Bridged Salen Zirconium Catalyst Affording Atactic Poly(propylene) and Isotactic Poly(α‐olefins)

“…Reaction with different cocatalysts and hydrolysis of complex 1. 4 ] are effective activators. The most intriguing result was the unexpected different stereospecificities observed for the polymerization of propene, which affords an ultrahigh-molecular-weight atactic polymer, and for the polymerization of higher a-olefins, which affords highly isotactic poly(1-butene), poly(1-pentene), and poly(1-hexene).…”

“…[3] This finding was traced to the well-known [2] reactivity of the imine functionality vs. the intramolecular reduction via 1,2-migratory insertion of metal-bound alkyl ligands. [4] The introduction of a methyl group at the Summary: A binaphthyl-bridged salen dichlorozirconium (IV) complex that displays an octahedral structure with a trans-O, cis-N, and cis-Cl arrangement was synthesized and tested as a precatalyst for ethylene and a-olefin polymerization. While use of methylaluminoxane (MAO) cocatalyst afforded poor catalytic activity, activation by mixtures of aluminium alkyls such as Al i Bu 3 and either MAO or [CPh 3 ][B(C 6 F 5 ) 4 ] resulted in reasonable polymerization activities for ethylene, propene, and higher a-olefins.…”

Synthesis and structures of dialkyl zirconium complexes with an [OSSO]-type bis(phenolate) ligand bearing a trans-1,2-cyclooctanediylbis(thio) unit

“…The solid was suspended in hexane, and the insoluble inorganic materials were removed by decantation. The solvent of the filtrate was removed in vacuo, and the residual solid was washed with hexane (2 mL) and dried in vacuo to afford 5 (565 mg, 90%) as (d,J ¼ 14 Hz,2H),4.17 (d,J ¼ 14 Hz,2H),6.75 (d,J ¼ 3 Hz,2H),7.58 (d,J ¼ 2 Hz,2H). 13 C NMR (100.5 MHz, C 6 D 6 ) d 3.…”