2-β-Benzothiazolyl-6-iminopyridylmetal dichlorides and the catalytic behavior towards ethylene oligomerization and polymerization

A series of 2-(2-benzothiazolyl)-6-(1-(arylimino)ethyl)pyridines and their metal (Fe or Co) complexes were prepared. All organic compounds were fully characterized by NMR, FT-IR spectra and elemental analysis, and all metal complexes were identified by FT-IR spectroscopic and elemental analysis. The molecular structures of representative metal complexes were confirmed by single-crystal X-ray diffraction and displayed the distorted trigonal bipyramid geometry. Upon activation with modified methylaluminoxane (MMAO), the iron pro-catalysts showed good catalytic activities up to the range of 107 g mol−1(Fe) h−1 in ethylene reactivity with the high selectivity for the vinyl-type products of both oligomers and polyethylene waxes; whereas the cobalt pro-catalysts showed moderate activities towards ethylene oligomerization. The correlations between metal complexes and their catalytic activities and products were investigated in detail under various reaction parameters and discussed.