The synthesis of titanium(iv), zirconium(iv) and hafnium(iv) complexes of Trost's semi-crown ligand is described.
DFT calculations indicate that the Lewis acidity of the catalytic metal center M (Ti, Zr, Hf) explains the redox-switchable activity observed for the ring-opening polymerization of ε-caprolactone by ferrocene derived metal complexes.
A series of group 4 complexes containing imine based bis-bidentate ligands were synthesized and used as catalysts for various polymerizations.