Peculiarities of the reactions between early lanthanide(III) ions and an anionic porphyrin

Insertion of lanthanide(III) ions into porphyrins shows a simultaneous ligand- and metal control. They may coordinate not only to the pyrrolic nitrogens but also to the peripheral substituents possessing O-donor atoms. Potential axial ligands can accelerate the coordination of the first porphyrin, but they can hinder that of another one.89