Solid-State and Solution Properties of Cationic Lanthanide Complexes of a New Neutral Heptadentate N4O3 Tripodal Ligand

The synthesis of the potentially heptadentate ligand tris[6-((2-N,N-diethylcarbamoyl)pyridyl)methyl]amine, tpaam, containing three pyridinecarboxamide arms connected to a central nitrogen is described. Lanthanide complexes of this ligand are prepared and characterized. The crystallographic structure of the complexes of three lanthanide ions (La, Nd, Lu) is determined. The lanthanide(III) complexes of tpaam crystallize as monomeric species (in the presence of chloride or iodide counterions) in which the ligand tpaam acts as a N403 donor....