Dual-side metallocene

Hild S, Rieger B, Troll C, Cobzaru C (2006) Elastomeric poly(propylene) from dual-side metallocenes reversible chain transfer and its influence on polymer microstructure. Macromol Chem Phys 207 665-683... 

Hild, S. Cobzaru, C. TroU, C. Rieger, B. Elastomeric polypropylene from dual-side metallocenes Reversible chain transfer and its influence in polymer microstructure. Macromol. Chem. Phys. 2006, 207, 665-683. 

Based on Chien s research results, Collins et al. modified the basic structure of the catalysts and also achieved elastic material [8,18,19]. In both cases the elastic properties of the polymers are justified in a block structure with isotactic and atactic sequences. In 1999 Rieger et al. presented a couple of asymmetric, highly active metallocene catalysts, e.g., the dual-side catalyst rac-[l-(9-r 5-fluorenyl)-2-(5,6-cyclo-penta-2-methyl-l-q5-indenyl)ethane]zirconium dichloride (Fig. 3). These catalysts allowed building of isolated stereoerrors in the polymer chain to control the tacticity and therefore the material properties of the polymers [9],... 

Hackmann M. Rieger, B. Metallocene catalysts in stereoselective synthesis. CaTTech 1997,2,19-91. 1. Cobzaru, C. Hild, S. Boger, A. Troll, C. Rieger, B. Dual-side catalysts for high and ullrahigh... 

The prudent choice of appropriate side chain protecting groups for Lys and Arg did pose a particular problem in combination with the chemical stability of the metallocenes and available resins and linkers. In order to study cellular uptake and localization in the nucleus of living cells, derivatives of 36 and 37 with an additional fluorescent dye attached to the peptide were also prepared. Cellular uptake and localization of these conjugates was then followed in different cell lines by fluorescence microscopy. This is the first study of sub-cellular localization of organometaiiic peptide derivatives with non-radioactive metals (see also Section 5.5.3.2 below for an example ofa dual radiometal- and fluorescent-labeled peptide). 

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