Rare Earth And Main Group Organometallic Complexes Supported By Pyrrolide Ligands: Synthesis, Structures And Reactivities

This thesis presents the studies on the synthesis, structures and catalytic activities of the lanthanide and main group organometallic complexes based on the pyrrolide ligands. It includes three parts.In the first part, the pyrrolide ligands H3L1(H3L1 = 1,9-bis(2-pyrrolyl)-2,5,8triazanona-1,8-diene) and H3L2(H3L2 = tris(pyrrolyl-?-methyl)amine) were synthesized. Then two yttrium complexes, [Y(L1)(THF)]2(1) and [Y(L2)(THF)3](2), supported by these ligands were synthesized and their structures were determined by single crystal X-ray diffraction. They were also characterized by NMR spectroscopy and elemental analysis. It was found that complexes 1 and 2 showed good activities towards the polymerization of ε-caprolactone.Secondly, the ligand H2L3(H2L3 = N,N’-(2,2-dimethylpropane-1,3-diyl)bis(1-(1H-pyrrol-2-yl)methanimine)) was synthesized. A series of aluminium complexes Al(L3)Me(3), Al(L3)Cl(4) and Al(L3)(OiPr)(5) were obtained. They were characterized by single crystal X-ray diffraction, NMR spectroscopy and elemental analysis. All the three complexes were good initiators for the polymerization of ε-caprolactone.Next, some heterometallic complexes were proposed to be synthesized. On purpose, the pyrrolide ligand H2L4(H2L4 = 1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine) was synthesized, and it reacted with scandium to give complex [Sc(L4)(HL4)THF]2?4THF(6). As it still had free pyrrolide proton, it was expected to react with a second metal to give heterometallic complex. But surprisingly, a trinuclear magnesium complex [Mg(L4)2(THF)2]3?3THF(7) was crystallized in the system with absence of heterometallic complex. Then another ligand H2L5(H2L5 = 2,2’-(hydrazine-1,2-diylidenebis(methanylylidene))diphenol) was synthesized for our target. Finally, a dinuclear lanthanide complex [Y(L5)1.5THF]2?2THF(8) was afforded, which had no free pyrrolide proton to proceed further reaction. Because of the large steric hindrance, the complexes 6 and 8 didn’t show any activity for the polymerization of ε-caprolactone.