Healable Luminescent Self-Assembly Supramolecular Metallogels Possessing Lanthanide (Eu/Tb) Dependent Rheological and Morphological Properties

Herein we present the use of lanthanide directed self-assembly formation (Ln­(III) = Eu­(III), Tb­(III)) in the generation of luminescent supramolecular polymers, that when swelled with methanol give rise to self-healing supramolecular gels. These were analyzed by using luminescent and 1H NMR titrations studies, allowing for the identification of the various species involved in the subsequent Ln­(III)-gel formation. These highly luminescent gels could be mixed to give a variety of luminescent colors depending on their Eu­(III):Tb­(III) stoichiometric ratios. Imaging and rheological studies showed that these gels prepared using only Eu­(III) or only Tb­(III) have different morphological and rheological properties, that are also different from those determined upon forming gels by mixing of Eu­(III) and Tb­(III) gels. Hence, our results demonstrate for the first time the crucial role the lanthanide ions play in the supramolecular polymerization process, which is in principle a host–guest interaction, and consequently in the self-healing properties of the corresponding gels, which are dictated by the same host–guest interactions.