Accessing highly linear polyethylenes by 2-(1-aryliminoethyl)-7-arylimino-6,6-dimethylcyclopenta[]pyridylchromium() chlorides

A series of 2-(1-aryliminoethyl)-7-arylimino-6,6-dimethylcyclopenta[ b ]pyridylchromium( iii ) chlorides (aryl = 2,6-Me 2 Ph ( Cr1 ), 2,6-Et 2 Ph ( Cr2 ), 2,6- i -Pr 2 Ph ( Cr3 ), 2,4,6-Me 3 Ph ( Cr4 ), 2,6-Et 2 -4-MePh ( Cr5 )) was synthesized and characterized using FT-IR and elemental analysis, and the molecular structure of complex Cr1 was confirmed by using single-crystal X-ray diffraction to present a distorted octahedral geometry around the chromium center. Upon activation with modified methylaluminoxane (MMAO) or ethylaluminium sesquichloride (EASC), all chromium pre-catalysts exhibit good activities towards ethylene polymerization for the highly linear polyethylene. The title complexes showed good activities toward ethylene polymerization producing highly linear polyethylenes, and catalytic behaviors of precatalysts were significantly affected by the substituents of chromium complexes.