Photoinduced rac/meso interconversions of bridged bis(indenyl) zirconium dichlorides

✍ Scribed by Walter Kaminsky; Anne-Meike Schauwienold; Frank Freidanck

• Book ID: 103997725
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 522 KB
• Volume: 112
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(96)00240-3

✦ Synopsis

Upon irradiation of a C,-symmetric rut-isomer of an ansu-zirconocene dichloride, an interconversion into the Cs-symmetric meso-form is observed until a photostationary state between the two diastereomers is reached. The final rac/meso-proportion and the interconversion rate depend on the structure of the different metallocenes. Results of cu-olefin polymerization catalyzed by [Me,Si(2-Me-4,6-'Pr,Ind),]ZrCl, rat and meso, respectively, and methylalumoxane (MAO) as cocatalyst are reported. In propene polymerization the rue-diastereomer shows the higher activity whereas in pentene, hexene, and octene polymerization the meso-isomer is significantly more active. For all polymers a lower molecular weight is found using the meso-diastereomer as catalyst.