1334702-68-9Relevant academic research and scientific papers
Binuclear half-metallocene chromium(III) complexes mediated ethylene polymerization with alkylaluminium as cocatalyst
Xu, Tieqi,Pan, Yu,Lu, Xiao-Bing
, p. 8643 - 8650 (2011/10/10)
Binuclear half-metallocene chromium complexes {Cp*[3-(CHNR)-2-O- C10H5]CrCl}2 [Cp* = C5Me 5; R = iPr (1), Ph (2), 2,6-iPr 2C6H3 (3)] based on 1,1′-binaphthyl ligands, as well as their mononuclear analogues Cp*[3-(CHNR)-2′- R′-2-O-C20H11]CrCl [R = iPr, R′ = nBuO (4), R = Ph, R′ = nBuO (5), R = 2,6- iPr2C6H3, R′ = nBuO (6), R = iPr, R′ = H (7)], were synthesized and characterized by mass spectrometry, elemental analysis, magnetic measurement, and UV-vis spectroscopy. The molecular structures of complexes 1, 3, 5 and 6 were further confirmed by single-crystal X-ray crystallographic analysis. When activated with a small amount of AlMe3, these binuclear complexes exhibited higher activities in catalyzing ethylene polymerization in comparison with their mononuclear analogues, affording high molecular weight polymers with unimodal molecular weight distributions. The highest activity up to 2.87 × 10 6 g PE (mol Cr)-1 h-1 was achieved in the catalyst system of complex 3 bearing a bulky 2,6-iPr 2C6H3 group on the imine nitrogen atom in the presence of 25 equiv. AlMe3 as activator at 20 °C. 13C NMR analysis indicates the resultant polymers are linear and no evidence on branch was found. The Royal Society of Chemistry 2011.
