ABSTRACT:The synthesis of iron(II) complexes with various tridentate di(imino)pyridine ligands and their potential as ethene oligomerization catalysts are described. The ligands are characterized by 1 H-and 13 C-NMR spectroscopy and the complexes only by mass spectrometry due to their paramagnetism. After activation either with methylalumoxane (MAO) or with a heterogeneous cocatalyst consisting of partially hydrolyzed trimethylaluminum and silica gel, the prepared complexes proved to be good catalysts for the oligomerization of ethene. 1-Octene, 1-hexene, and 1-decene were the major products, formed in very high isomeric purity (99.9 %).

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Fabrication of pellets with defined pore‐size distribution. The fabrication of porous alumina‐pellets of high mechanical strength and with a well defined pore‐size distribution by pelletization and by extrusion is described. Macropores can be introduced through solid material which is vaporized after agglomeration; the content of macropores can thereby be chosen within a rather wide range. The amount of micropores in the pellets can be controlled by thermal treatment (sintering). Mechanical strength is obtained if the primary particles are connected by bridges of solid material, generated from substances dissolved in the liquid which fills the pores before drying. The mechanism and the procedure leading to the formation of porous alumina‐pellets are also applicable if silica or zeolites are to be agglomerated into porous pellets of high mechanical strength.

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