Helically twisted molecular architectures are critical motifs in both biology and synthetic supramolecular chemistry,with unique functional properties derived from their chiral geometries.Although lemniscular(figure-e...Helically twisted molecular architectures are critical motifs in both biology and synthetic supramolecular chemistry,with unique functional properties derived from their chiral geometries.Although lemniscular(figure-eight)macrocycles with a noncontact crossover point have attracted increasing interest,their metallosupramolecular analogs remain underexplored,largely because of synthetic challenges that hinder precise control.Herein,we report a coordination-driven strategy for the controlled construction of lemniscular metallacycles by exploiting the linear coordination geometry of Ag^(l) and Au^(l) complexes containing N-heterocyclic carbene(NHC)ligands.The key to this approach is the design of a bis-NHC imidazolium ligand containing helicene moieties,which promotes homochiral helicene dimerization and suppresses noncrossover macrocycle formation.Ag^(l) and Au^(l) -NHC lemniscular architectures were synthesized via this method,and the Au'complex was validated through multiple synthetic pathways.The generated structures were characterized via electrospray ionization mass spectrometry,ultraviolet-visible absorption and fluorescence emission spectroscopy,X-ray crystallography,and density functional theory calculations,confirming the formation of the target metallacycles.Notably,this work addresses the long-standing scarcity of metallosupramolecular lemniscular systems,increases the structural diversity of macrocycles,and establishes a platform for the systematic investigation of the emergent functionalities of these complexes.展开更多
基金support from the National Natural Science Foundation of China(22025107,92461302,22301040)the National Youth Top-notch Talent Support Program of China,the Shaanxi Postdoctoral Science Foundation Project(2023BSHYDZZ128)+1 种基金the Xi'an Key Laboratory of Functional Supramolecular Structure and Materialsthe FM&EM International Joint Laboratory of Northwest University.
文摘Helically twisted molecular architectures are critical motifs in both biology and synthetic supramolecular chemistry,with unique functional properties derived from their chiral geometries.Although lemniscular(figure-eight)macrocycles with a noncontact crossover point have attracted increasing interest,their metallosupramolecular analogs remain underexplored,largely because of synthetic challenges that hinder precise control.Herein,we report a coordination-driven strategy for the controlled construction of lemniscular metallacycles by exploiting the linear coordination geometry of Ag^(l) and Au^(l) complexes containing N-heterocyclic carbene(NHC)ligands.The key to this approach is the design of a bis-NHC imidazolium ligand containing helicene moieties,which promotes homochiral helicene dimerization and suppresses noncrossover macrocycle formation.Ag^(l) and Au^(l) -NHC lemniscular architectures were synthesized via this method,and the Au'complex was validated through multiple synthetic pathways.The generated structures were characterized via electrospray ionization mass spectrometry,ultraviolet-visible absorption and fluorescence emission spectroscopy,X-ray crystallography,and density functional theory calculations,confirming the formation of the target metallacycles.Notably,this work addresses the long-standing scarcity of metallosupramolecular lemniscular systems,increases the structural diversity of macrocycles,and establishes a platform for the systematic investigation of the emergent functionalities of these complexes.
