Building multi-color emitters with tailored lanthanide-based supramolecular metallogels

Multicomponent lanthanide-based metallogel offers unique prospects to access versatile, dynamic supramolecular soft materials with hierarchical stimuli-responsiveness and tunable functions, particularly for applications in the optical display field. In this work, a novel ligand L bearing classical coordinating terpyridine (tpy) and hosting 24-Crown-8 (24C8) moieties was synthesized with a function-oriented design principle, which further allowed the complexation between L and a series of lanthanide ions (Ln). Interestingly, several L-Ln complexes with 1:1 stoichiometry were found to be able to gel the solvent toluene/CH3CN (1:1), and thus lanthanide-based metallogels were successfully prepared. The L-Eu and L-Tb gel was found to be emissive and further utilized to produce a white light emitter through fine adjustment of stoichiometry among Eu, Tb, and L. Importantly, the multicomponent gel strategy was employed, and additional non-coordinating chromophores were introduced into the metallogel system. Thus a broad-spectrum of emission was achieved, and these multicomponent emissive gels were successfully applied as a photo printer. The metallogels also showed multiple stimuli-responsiveness such as pH, guest molecules thanks to the anchoring of predesigned functional moieties such as tpy and 24C8 on the ligand L. It is assumed that our multicomponent metallogel research shown here may open new avenues towards the design and preparation of intelligent and tunable hybrid lanthanide-based optical materials.