Synthesis And Structure Study Of Penta-heterocyclic Transition Metal Catalysts For Olefin Polymerization

In this work, some new olefin polymerization/oligomerization catalyst systems had beendesigned and synthesized based on Brookhart bis(imino)Pyridine late transition metal catalyst.Remarkable changes in metal complexing ability and catalytic activity of metal complexescould been caused by minor changes in the catalyst ligand structures. New typepenta-heterocyclic transition metal catalysts had been obtained through modifying or changingthe ligands of Brookhart bis(imino)Pyridine transition metal catalysts in electronic effects andsteric effects.The main studies are as follows:Using2-acetyl pyrrole，2-acetyl thiophene and2-acetyl furan and a couple of aromaticamines, three series of compounds, eleven mono(imino)pyrrole compounds (1a~1n), elevenmono(imino)thiophene compounds (2a~2n) and eleven mono(imino)furan compounds (3a~3n)were prepared under the microwave irradiation by Schiff-base condensation reaction. Thesestructures were characterized by X-ray single crystal diffraction,1H NMR, IR, MS andelemental analysis, and these crystal structures had been determined. The spatial structures ofthese ligands had been discussed by the analysis of data on the use of molecular structuralcharacterization in depth. Meanwhile, the reaction mechanism of such Schiff-basecondensation reaction were also discussed. A series of novel centrosymmetric nickel (II)complexes (4a~4j) had been obtained by the reaction between mono(imino)pyrrolecompounds and transition metal Ni (II) chloride. These structures were characterized by X-raysingle crystal diffraction. Also, The spatial structures of these complexes had been discussedby the analysis of data on the use of molecular structural characterization in depth. Noindication showed the reaction occurred between mono(imino)thiophene compounds,mono(imino)furan compounds and transition metal Ni (II), Co (II) chloride by liquid-phasereaction and hydrothermal reaction respectively. With the oxygen and sulfur atoms of the furanand thiophene core of these ligands being rather poor donors, the corresponding complexeshad not obtained.