Progress of olefin polymerization by metallocene catalysts

New C-1-symmetric metallocenes such as [Me2C(PhCp)(Flu)ZrCl2, [Me(3)Pen(Flu )]ZrCl2, [PhMe(3)Pen(Flu)]ZrCl2 were synthesized and used for the polymeriz ation of propene by higher polymerization temperatures. Different polypropy lene micro structures were obtained. Important for industrial processes are the high molecular weights of the polymers produced by the pentalenelike c atalysts, which are very stable by higher temperatures. For synthesis of sy ndiotactic polystyrene and new substituted half-sandwich titanocenes are us ed such as 1,3-Me2CpTiCl3, Me4CpTiCl3, PhCpTiCl3, cyclohexyl-CpTiCl3 If the y are fluorinated, the activity for the production of syndiotactic polystyr ene can be increased 10 times. The synthesized polymer shows a high melting point of 275 degreesC.