Neue aromatische Bisguanidin-Kupfer-Komplexe und ihre Anwendung in der ATRP / New Aromatic Bisguanidine Copper Complexes and Their Application in ATRP

We synthesized and structurally characterized two new copper(II) monochelate complexes with the ligand 2,2'-(1,2-phenylenebis(1,1,3,3-tetramethyl)guanidine) (TMG2b), [Cu(TMG2b)Cl2] and [Cu(TMG2b)Br2]. Single-crystal structure determination has shown that the complexes [Cu(TMG2b)Cl2] and [Cu(TMG2b)Br2] both crystallize in the orthorhombic space group Pbcn. The copper atoms in all complex cations reside in a coordination environment between tetrahedral and square-planar geometry. Furthermore, the application of the copper complexes with TMG2b as ligand in atom transfer radical polymerization (ATRP) was investigated with styrene as monomer. This study has shown a controlled polymerization process with moderate conversions, but excellent molecular weight distributions that are evidence of a well-controlled ATRP. However, small changes in the ligand structure can have a high impact, and therefore process optimizations and ligand tuning are necessary to develop highly active catalysts for ATRP.