Synthesis And Characterization. New Large Anionic Complexes,

The development of olefin polymerization catalyst has been paid much attention in academia and industry.In the past 50 years,three catalytic systems,Ziegler-Natta catalysts,metallocene catalysts transition metal catalysts,have been developed.The co-catalysts in a traditional two-component Ziegler-Natta catalyst system are usually main group organometallic compounds and play a very important role in the development of single site catalyst system for olefin polymerization.In some cases,the activity of a catalyst depends highly on the types of anions,the weaker the coordinating ability to the caion of an anion is,the higher the catalyst's activity.Bochmann and LaPoint's team used conjugated anion to bridge two molecules of FAB for formation of large anions.They found that a metallocene catalyst system with one of these anions showed higher catalytic activity for polymerization of olefins.This synthetic method has a major advantage:easier access to starting materials and simpler synthetic route.Based on this thought,we employed the corresponding anion of polydentate nitrogen ligands to connect tri(perflurophenyl) boron(FAB) and to form large anions with much weaker coordinating ability to cations.Thus we synthesized more than 10 ion association compounds with first transition-metal elements.The recent progress of olefin polymerization catalysts and their promoters were discussed in the first part of this thesis and particularly their types,properties,advantages,disadvantages and applications in industry were emphasized.In the second part potassium benzoimidazolate,potassium benzotriazolate,potassium salts of three pyridyl tetrazolylazole and potassium 5-phenyl tetrazolate were synthesized and characterized by elemental analysis and IR.In the third part potassium salts of large anions were synthesized using the potassium salts prepared in the second part and FAB in toluene in the presence of 18-Crowd-6.The products were transferred to the corresponding silver salts by metathesis.The silver salts reacted then with MnCl₂ to prepare the final products.As a result, 15 new associate ion compounds were produced,of which the components and structures of 10 kinds of manganese and potassium salts were characterized by elemental analysis,IR,and other techniques; in particular,part of products were characterized by ¹¹B,¹³C,¹⁹F and ¹HNMR techniques.Through the characterizations,it showed that our new manganese compounds have larger anions than those reported and thus have weakly coordinating ability with cations.These complexes will be tested as cyclopentadiene polymerization initiators later.