The Construction of Homochiral Lanthanide Quadruple‐Stranded Helicates with Multiresponsive Sensing Properties toward Fluoride Anions

Abstract

A series of unique homochiral lanthanide tetranuclear quadruple-stranded helicates have been self-assembled controllably by using the intrinsic advantages of chiral bridging ligands, (S)-H L and (R)-H L, and lanthanide ions with high coordination numbers. The self-assembly process of these chiral helicates not only ensures the structural stability and quadruple-stranded feature of lanthanide cluster in the solid state and solution, but also achieves effective transfer and amplification of the chirality code from the ligand to a higher supramolecular level. Moreover, through using optical rotation, circular dichroism spectra analysis, and luminescence measurements, we demonstrate that these chiral lanthanide helicates could serve as sensitive and multi-responsive sensors to recognize and detect F anions based on the change of chiral signal and NIR luminescence simultaneously, which represents a meaningful exploration for developing functional lanthanide-based polynuclear clusters.

Sorting Phenomena and Chirality Transfer in Fluoride-Bridged Macrocyclic Rare Earth Complexes

“…Another important issue in the synthesis of elaborate enantiopure metal complexes or supramolecular assemblies is chirality transfer, − e.g., the transmission of chiral information from enantiopure ligands to metal centers. While there are many chiral transition metal complexes with well-defined stable configurations, the control over chirality of lanthanide complexes, in particular polynuclear complexes, − ,− is more difficult due to the lack of spatial preferences, lability, and high-coordination numbers of these ions. For similar reasons recognition and self-sorting phenomena ,− ,, in lanthanide systems are not so well explored in comparison with the systems based on stable organic compounds or more rigid and inert transition metal complexes.…”

Anion-Coordination-Driven Assembly of Chiral Quadruple and Single Helices Controlled by Countercations

“…Helical structures are a particularly important class of supramolecular motifs both in biosystems and in functional materials . Chemists have designed numerous artificial helical systems that can serve as mimics of biological molecules or exhibit unique properties, including discrete and/or infinite single-stranded (foldamer), , double-, , triple-, , and multiple-stranded, , as well as circular helices. , Different strategies, such as metal coordination, hydrogen bonding, , π-stacking, , etc., were used to construct these structurally elegant systems, among which the metal-coordination-driven assembly of the metallo-helicates is perhaps the most widely applied one.…”

Directed Self-Assembly of Trimeric DNA-Bindingchiral Miniprotein Helicates

“…The slow development in the applied chemistry of metal helicates ultimately derives from the shortcomings associated with the classic synthetic approaches with organic ligands that complicate the structural control of the final helicates (i.e., oligomerization state, relative orientation of asymmetric ligands, supramolecular helicity) and hampers their efficient structural and functional optimization. Indeed, despite some noteworthy examples (Haino et al, 2009 ; Cardo et al, 2011 ; Howson et al, 2012 ; Chen et al, 2017 ; Mitchell et al, 2017 ; Guan et al, 2018 ), no general approach for the efficient and versatile stereoselective synthesis of helicates is yet available, making of these systems a challenging test case to demonstrate the potential of peptides for the controlled assembly of metallostructures.…”