1210052-82-6Relevant articles and documents
Same ligand, different metals: Diiodo-salan complexes of the group 4 triad in isospecific polymerization of 1-hexene and propylene
Cohen, Ad,Kopilov, Jacob,Lamberti, Marina,Venditto, Vincenzo,Kol, Moshe
, p. 1689 - 1691 (2010)
The synthesis of a salan ligand featuring diiodo-phenolate rings, the dibenzyl complexes of the ligand and the polymerization of 1-hexene and propylene by the complexes was reported. The zirconium complex led to the most active catalyst with an activity of 3800g mmol-1 h-1, the hafnium and titanium complexes exhibited lower activities of 1500g mmol -1 h-1. GPC analysis showed that the Zr catalyst led to a low molecular weight poly(1-hexene) of Mw=1400 and PDI=2.0. The Zr catalyst led to poly-(1-hexene) of 33%, which is low, but higher than that obtained from the corresponding dibromo-Salan-Zr complex. Chain-end analysis of the low-Mw polypropylene derived from the Zr catalyst revealed vinylidene and n-propyl groups as major chain ends, supporting a regular 1,2-insertion prior to a hydride-transfer termination. Several polypropylene samples produced by the titanium catalyst were analyzed by differential scanning calorimetry, which showed the melting transitions in the temperatures of 120.9-123.8°C.
