Heteroatom-Containing Monocene Rare Earth Metal Complex Catalytic System And Synthetic Rubber Polymerization Process

In this paper,two indeno[1,2-b]indole derivatives(C15H9N(C6H6)R)(R=H(L1),Ph(L2))were prepared by the Fishers indole synthesis method.The C15H9N(C6H6)Li were reacted with trimethylchlorosilane and 2-chloromethylpyridine,respectively,prepare(C15H9N(C6H6)R)(R=TMS(L3),CH2-Py(L4)).The Lithium salts of the four heteroatom-containing cyclopentadienyl ligands of lithium salt(C15H9N(C6H6)R)Li were reacted with 1 equiv.of LnX3(THF)n(X=Cl,(Ln=Y,n=3.5;Ln=Gd,n=3.8;Ln=Er,n=1.7;Ln=Lu,n=3);X=Br,Ln=Nd,n=4)in tetrahydrofuran or toluene.The reactions gave the desired complexes(C15H9N(C6H6)R)LnX2(THF)n(X=Cl,(R=H,Ph,TMS,Ln=Y,n=3.5;R=H,Ln=Gd,n=3.8;R=Ph,Ln=Er,n=1.7;R=H,Ln=Lu,n=3);X=Br,R=Ph,Ln=Nd,n=4).The complexes were then reacted with 2 equivalents o-C6H4NMe2CH2Li(ortho-dimehylaminobenzo-lithium)in toluene or tetrahydrofuran to obtain a series of heteroatom-containing monocene bisalkyl complexes,(C15H9N(C6H6)R)Ln(CH2C6H4NMe2-o)2(R=H,Ln=Y(1a),Nd(1b),Gd(1c),Lu(1d);R=Ph,Ln=Y(2a),Nd(2b),Gd(2c);R=TMS,Ln=Y(3a)).In addition,when selecting the rare earth centers SC and Lu for reaction,we accidentally obtained(C15Hi0N(C6H6))2Sc(CH2C6H4NMe2o)(2e)metallocene rare earth monoalkyl complex.While(C15H9N(C6H6)CH2Py)ScCl2(4e)metallocene rare earth dichlorides were obtained when the rare earth center Sc was selected to react with(C15H9N(C6H6)CH2Py(L4).Aternary catalytic system of Ph-Y/[Ph3C][B(C6F5)4]/TIBA with toluene as the solvent was identified for the synthesis of intercalated polystyrene by screening the components of the heteroatom-containing monocene rare earth metal complexes synthesized above.The ternary catalytic system was used to study the research polymerization process and to determine the optimum polymerization process for styrene polymerization at 70℃ for 40 min with[Ln]/[Al]/[St]=1/5/500(mol/mol/mol),where the monomer conversion could reach 86.79%as well as the catalytic activity was 6.779 × 104g-mol-1·h-1,and the syndiotacticity of polystyrene is more than 89%.Finally,the effect of the above catalytic system on styrenebutadiene copolymerization was investigated and it was found that the copolymers were probably block structures with a low content of polystyrene chain segments of about 11.88%mass fraction.