Heterolepic β‐Ketoiminate Zinc Phenoxide Complexes as Efficient Catalysts for the Ring Opening Polymerization of Lactide
Dr. Swarup Ghosh,
Pascal M. Schäfer,
Dr. Dennis Dittrich,
Dr. Christoph Scheiper,
Dr. Phillip Steiniger,
Dr. Gerhard Fink,
Agnieszka N. Ksiazkiewicz,
Alexander Tjaberings,
Dr. Christoph Wölper,
Prof. Dr. André H. Gröschel,
Prof. Dr. Andrij Pich,
Prof. Dr. Sonja Herres‐Pawlis,
Prof. Dr. Stephan Schulz
Affiliations
Dr. Swarup Ghosh
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Pascal M. Schäfer
Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany
Dr. Dennis Dittrich
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Dr. Christoph Scheiper
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Dr. Phillip Steiniger
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Dr. Gerhard Fink
Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany
Agnieszka N. Ksiazkiewicz
Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
Alexander Tjaberings
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) NanoEnergieTechnikZentrum Carl-Benz-Str. 199 47057 Duisburg
Dr. Christoph Wölper
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Prof. Dr. André H. Gröschel
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) NanoEnergieTechnikZentrum Carl-Benz-Str. 199 47057 Duisburg
Prof. Dr. Andrij Pich
Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
Prof. Dr. Sonja Herres‐Pawlis
Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany
Prof. Dr. Stephan Schulz
Faculty of Chemistry University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE) Universitätsstr. 7, S07 S03 C30 D-45141 Essen
Abstract Zinc phenoxide complexes L1ZnOAr 1–4 (L1=Me2NC2H4NC(Me)CHC(Me)O) and L2ZnOAr 5–8 (L2=Me2NC3H6NC(Me)CHC(Me)O) with donor‐functionalized β‐ketoiminate ligands (L1/2) and OAr substituents (Ar=Ph 1, 5; 2,6‐Me2‐C6H3 2, 6; 3,5‐Me2‐C6H3 3, 7; 4‐Bu‐C6H4 4, 8) with tuneable electronic and steric properties were synthesized and characterized. 1–8 adopt binuclear structures in the solid state except for 5, while they are monomeric in CDCl3 solution. 1–8 are active catalysts for the ring opening polymerization (ROP) of lactide (LA) in CH2Cl2 at ambient temperature and the catalytic activity is controlled by the electronic and steric properties of the OAr substituent, yielding polymers with high average molecular weight (Mn) and moderately controlled molecular weight distribution (MWDs). 1 and 5 showed a living polymerization character and kinetic studies on the ROP of L–LA with 1 and 5 proved first order dependencies on the monomer concentration. Homonuclear decoupled 1H‐NMR analyses of polylactic acid (PLA) formed with rac‐LA proved isotactic enrichment of the PLA microstructure.
