Self‐Assembly of a Tripodal Terpyridine Based Ligand with Luminescent Lanthanide Ions in Solution and Soft Material

Abstract The tripodal 1,3,5‐benzene tricarboxamide (BTA) ligand functionalized with terpyridine ( 1 ) is used to self‐assemble with Ln(III) ions (Ln = La, Sm, Eu, Gd, Tb, Yb, and Lu) in solution and within soft material (supramolecular metallogels). Stability constants for 1:1 and 3:2 ( M:L ) assemblies formed in MeOH are determined using nonlinear regression analysis of UV–vis absorption and emission titrations revealing a parabolic relationship between the binding constants values and the ionic radii of Ln(III) ions. The formation of gels using ligand 1 in MeOH‐H ₂ O at 0.6 wt.% and their modification, by diffusing the Ln(III) ions through them is described. The latter leads to both crosslinking of already self‐assembled ligands, as well as modulating their physical properties as demonstrated by photophysical, rheological, and morphological studies leading to significant changes in the in situ morphology.