Dispersion Forces-Driven Hierarchical Assembly of Protein-Like Lanthanide Octamers and Emergent CPL.

Abstract

Hierarchical self-assembly driven by non-covalent interactions is a prevalent strategy employed by nature to construct sophisticated biomacromolecules, such as proteins. However, the construction of protein-like superstructures that rely on weaker dispersion forces-driven hierarchical assembly remains largely unexplored. Here, we report the first example of dispersion forces driving the high-order assembly of the lanthanide trinuclear circular helicate [HNEt₃]₃[Eu₃(LL)₆] (ΔΔΔ-1) into a protein-like lanthanide octamer ((ΔΔΔ-1)₈-2). Within the octamer, the forty-eight (48) menthol groups on the ligands and eighty-four (84) 1,4-dioxane solvent molecules contribute to enhanced dispersion forces through conformational adaptation and size-matching effects. These enhanced dispersion forces not only drive the formation of the hierarchical superstructure but also result in a four-level chirality transfer from the menthol to the octamer. Benefiting from the homochirality of Eu³⁺, the octamer is endowed the strong circularly polarized emission (|glum| = 0.34, Φoverall = 41%). This understanding of how dispersion forces drive hierarchical self-assembly provides a foundation for the directed fabrication of more fascinating superstructures.