Novel bi- and hexanuclear titanium (IV) complexes: Synthesis, structure and catalytic activities in oligo- and polymerization of 1-hexene

Abstract

Novel bi- and hexanuclear titanium (IV) complexes with 2,2′-bis-(hydroxymethyl)-1,1′-biphenole derivative were synthesized. Structure of complexes 4–5 were established by X-ray diffraction. Resulting catalytic systems obtained by pre-catalysts activation by diethylaluminum chloride or ethyl aluminum sesquichloride were active in the 1-hexene oligomerization. Replacement of alkylaluminumchlorides by a {3Et2AlCl + Bu2Mg} binary system results in formation of predominantly isotactic, high molecular weight poly-1-hexene (content of isotactic pentad mmmm 70%). Systems treated with “traditional” activators – MAO and AlR3 were not active.