Preparation and structures of 6-and 7-coordinate salen-type zirconium complexes and their catalytic properties for oligomerization of ethylene
2005 (English)In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 690, no 17, 3929-3936 p.Article in journal (Refereed) Published
A series of salen-type zirconium complexes of the general formula LZrCl2 (L = N,N '-ethylenebis(salicylideneiminate), 3a; N,N '-ethylenebis(3,5-di-tert -butylsalicylideneiminate), 3b; N,N '-ethylenebis(5-methoxysalicylidenciminate), 3e; N,N '-o-phethylenebis(5-chlorosalicylideneiminate), 3d; N,N '-ethylenebis(5-nitrosalicylideneiminate), 3e; N,N '-o-phenylenebis(salicylideneiminate), 4a; N,N '-o-phenylenebis(3,5-di-tert-butylsalicylideneiminate), 4b; N,N '-o-phenylenebis(5-methoxysalicylideneiminate), 4c; N,N '-o-phenylenebis(5-chloro-salicylideneiminate), 4d) were prepared. The crystal structures of 6- and 7-coordinate zirconium complexes 4b and [4b center dot OCMe2] were determined by X-ray crystallography, which reveals that a salen-type zirconium complex possesses a labile coordination site on the Zr center with a relatively stable framework and that the coordination and the dissociation of O-donor molecules occur readily at this site. The catalytic properties of 3(a-e) and 4(a-d) were studied for ethylene oligomerization in combination with Et2AlCl as co-catalyst. Complex 3c featuring a methoxy-substituted salen ligand displayed higher activity than its analogous precursors having chloro and nitro groups as substituents. The catalytic reactions by 3(a-e) and 4(a-d) gave C-4-C-10 olefins and low-carbon linear (alpha-olefins in good selectivity.
Place, publisher, year, edition, pages
2005. Vol. 690, no 17, 3929-3936 p.
zirconium complexes, Shiff bases, salen ligands, ethylene oligomerization, low-carbon alpha-olefins, crystal structures, acen = n,n'-ethylenebis(acetylacetoneiminate), quadridentate schiff-base, olefin polymerization, crystal-structures, thermal-stability, chelate ligands, metal-complexes, ti, reactivity, chemistry
IdentifiersURN: urn:nbn:se:kth:diva-15050DOI: 10.1016/j.jorganchem.2005.05.027ISI: 000231945900007ScopusID: 2-s2.0-25444464686OAI: oai:DiVA.org:kth-15050DiVA: diva2:333091
QC 201005252010-08-052010-08-05Bibliographically approved