Lanthanide Centered and Circular Polarized Luminescence (CPL) From Tb(III) Complexes Made From Structurally Simple Methoxy‐Phenyl and Phenol‐Derived Pyridyldiamide (pda) Ligands

ABSTRACT

The chiral pda derived anisole ligands L1a [ 1( R,R )] and L1b [ 1( S,S )], along with their phenol derivatives L2a [ 2( R,R )] and L2b [ 2( S,S )], were used for lanthanide‐directed synthesis of their respective Tb(III) complexes. Under thermodynamic control, the 3:1 (ligand:metal) enantiomerically pure assemblies were formed, including the Tb(III) complex of L1b ( S,S ) which was structurally characterized by x‐ray crystallography. These Tb‐complexes exhibited Tb(III)‐centered emission upon ligand excitation, demonstrating efficient sensitization of their ⁵ D ₄ excited states. Their self‐assembly formation under kinetic control was also investigated through monitoring the ground, the singlet and the Tb(III) excited state changes in situ and analyzed using non‐linear regression fitting of the changes in both the ground and the exited states. Moreover, their chiroptical properties were also probed by using both circular dichroism (CD) and circular polarized luminescence (CPL) spectroscopy, where all the complexes displayed signals of equal and opposite handiness for given enantiomers.