Lucas Stieglitz, M.Sc.

Doktorand

Raum: 3043 (CRC)

Telefon: 089-289-54184

email: lucas.stieglitz(at)makro.ch.tum.de

One of the major milestones in the history of polymerization was without a doubt the discovery of Karl Ziegler in 1953, that transition-metal halides combined with aluminum-compounds can polymerize ethylene to polyethylene, even under ambient pressure. Just one year later, Giulio Natta used the concept of this so called coordinative polymerization to polymerize propylene to polypropylene. The coordinative polymerization was investigated over the years in more detail by changing the reaction parameters and co-catalysts. This led to the discovery of metallocene-type catalysts, such as Cp₂TiCl₂ by Natta and Breslow in 1957. By using these single-site catalyst systems, various parameters of the received polypropylene, such as the tacticity, molecular weight and melting transition, can easily be fine-tuned.

My research project:

My work focusses on the synthesis of group IV-metallocenes with different symmetries. For this aim, the work in the laboratory is diversely designed and starts with classic (metal-)organic chemistry to isolate the desired ligand systems and catalysts. Subsequently, these catalysts are examined in the polymerization of propylene under various conditions to form ultrahigh molecular weight polypropylene. The obtained polymer is then analyzed via GPC-, NMR- and DSC-analysis.

Publications:

1. Lucas Stieglitz, Tim Maximilian Lenz, Andreas Saurwein, Bernhard Rieger, Angew. Chemie 2022, accepted manuscript
   "Perfectly Isotactic Polypropylene upon In Situ Activation of Ultrarigid meso Hafnocenes"
    
2. Lucas Stieglitz, Daniel Henschel, Thomas Pehl, Bernhard Rieger, Organometallics 2021, 40, 24, 4055–4065, Cover page
   "In Situ Activation: Chances and Limitations to Form Ultrahigh Molecular Weight Syndiotactic Polypropylene with Metallocene Dichlorides"
    
3. Ruikai Wu, Wenyu Klingler Wu, Lucas Stieglitz, Sabyasachi Gaan, Bernhard Rieger, Manfred Heuberger,
   Coordination Chemistry Reviews 2023, vol.474, 214844
   "Recent advances on α-diimine Ni and Pd complexes for catalyzed ethylene (Co)polymerization: A comprehensive review"

Related Publications on the project:

1. H.H. Brintzinger, D. Fischer, R. Mülhaupt, B. Rieger and R.M. Waymouth, Angew. Chem. Int. Ed. Engl. 1995, 34, 1143-1170.
   “Stereospecific Olefin Polymerization with Chiral Metallocene Catalysts”

2. M. R. Machat, D. Lanzinger, A. Pöthig and B. Rieger, Organometallics 2017, 36, 399-408.
   “Ultrarigid Indenyl-based Hafnocene Complexes for the Highly Isoselective Polymerization of Propene: Tunable Polymerization Performance Adopting Various Sterically Demanding 4-Aryl Substituents”

3. M. R. Machat, D. Lanzinger, M. Drees, P. J. Altmann, E. Herdtweck, B. Rieger, Macromolecules 2018, 51, 914−929.
   “High-Melting, Elastic Polypropylene: A One-Pot, One-Catalyst Strategy toward Propylene-Based Thermoplastic Elastomers