Synthesis Of N,O-bidentate Complexes And Their Catalytic Performance

Among the organometallic chemistry,the synthesis and catalytic performance of organometallic complexes containing nitrogen and oxygen heteroatoms are of current interest rearch areas,especially the salicylaldimine and reduction Schiff metal complexes.Not only the procedures to synthesize them are convenient and easy,but also their main group or transition metal complexes have been employed in many areas,such as,asymmetric catalysis reaction,ring-opening polymerization of lactide and olefin polymerization,and so on.In this paper,we synthesized and characterized two kinds of reduced salicylaldimine N,O-bidentate ligands and a series of monoanionic and dianionic transition metal complexes.Activated with methylaluminoxane(MAO),we studied the catalytic performance of the group IVB metal complexes on olefin polymerization,and discussed the influence of reaction temperature,amount of cocatalyst and reaction time on the catalytic activity.There are three parts in this thesis.2g,M=Ni,2e,M=Zr 2h,M=Cu,2f,M=HfPart?:It simply introduced the structure characteristics and styles of some N,O-bidentate and multidentate ligands,and reviewed their application in asymmetric catalysis reaction,ring-opening polymerization of lactide and olefin polymerization.Part?:We synthesized two kinds of reduced salicylaldimine N,O-bi-dentate ligands,which are 4,6-di-tert-butyl-2-(((1'-phenylethyl)amino)-methyl)phenol(2a)and 4,6-di-tert-butyl-2-((benzhydrylamino)methyl)-phenol(2b).Then we prepared some monoanionic metal(Li?Ti?Zr?Hf?Ni?Cu)complexes 2c-2h(Scheme 1)and dianionic metal(Li?Zr?Zn)complexes 2i-2k(Scheme 2).And the structures of all metal complexes were confirmed by NMR,elemental analysis and X-ray single diffraction.2k 2jPart ?:The catalytic behavors of all obtained group IVB metal complexes 2d?2e?2f?2j as catalysts for the olefin polymerization were investigated.In the presence of co-catalyst(MAO),the zirconium and titanium complexes exhibited moderate activities toward ethylene polymerization,and we obtained Utral-high molecular weights polyethylene,their molecular weights were(1.1?2.32)×106 g/mol.However,the hafnium complex was almost no activity towards ethylene polymerization.