Multicomponent Chiral Self-assembly And Properties Of Benzimidazole Derivatives

Chirality is a fundamental feature of nature.Different kinds of chiral spectroscopies have been used to recognize and characterize the chirality information.Among them,circularly polarized luminescence(CPL)has attracted more and more attention due to its potential applications in optical sensors,photoelectric devices,spintronic devices,and information storages.Furthermore,quantitative detection and recognition of chiral compounds continues to be of crucial importance in many areas such as the discovery and optimization of natural products,materials,and pharmaceuticals.Chiroptical methodologies are the rapidly developing methods to recognize,sense and separate the chiral species.In this manuscript,multicomponent chiral self-assembly of benzimidazole derivatives was used to regulate the supramolecular chirality and chiroptical properties of CPL-active materials.On this occasion,luminescence dissymmetry factors(glum),wavelength scopes and handedness of CPL can be flexibly regulated.Besides,quantitative ee%detection of chiral acids based on coassembly with benzimidazole derivatives via hydrogen bonds has been successfully constructed.The main research contents and results of this manuscript are as follows:(1)We report a highly accurate quantitative ee%detection of chiral acids based on the coassembly between achiral benzimidazole derivatives and chiral acids,wherein the chiral transfer occurred from chiral acids to benzimidazole probes accompanied by the emergence of circular dichroism(CD)signals.A well-defined linear correlation between CD dissymmetry factor(gabs)and chiral acids ee%with a correlation coefficient(R2)up to 0.999 was accomplished in such coassembled systems.Except for the linear gabs/ee%dependence,both positive and negative nonlinear gabs/ee%dependence with high R2(0.999 and 0.998)were also observed.Therefore,the application for the detection of natural and synthesized chiral acids ee%can be achieved by relying on the fine correlations with gabs.(2)We show the programmable coassembly of pyridine-cored benzimidazole derivatives with intrinsic propeller structure,which shall form binary and ternary aggregates with chiral acids as well as metal ions through H-bonds and metal-ligand coordination interactions in an orthogonal manner,to enhance and flexibly control the chiroptical properties.Solid-state X-ray structures of pyridine-benzimidazole derivatives suggested they adopted the propeller molecular chirality structure.Competition between molecular and supramolecular chirality and dynamic binding toward enantiomers of pyridine-benzimidazole derivatives were observed in the coassembly systems based on the chiroptical responses and molecular dynamic simulation(MD).Compared to the intrinsic racemic assemblies,coassembly systems produced chiroptical responses including the Cotton effect and CPL with relatively high dissymmetry factors.Furthermore,chiroptical responses were further controlled by introducing metal ions,achieving inverted handedness and tunable dissymmetry factors.This work provides feasible strategies to efficiently regulate and enhance the chiroptical properties of intrinsic aromatics via multiple interactions,which also expresses great potential in quantitative ee%sensing for chiral acids.(3)Achiral fluorescent 1-pyrenecarboxylic acid-benzimidazole derivative(PBI)was synthesized,of which chiroptical properties of PBI coassembled with chiral acids(TA and MA),octafluoronaphthalene(OFN)through hydrogen bonds between benzimidazole and chiral acid as well as Arene-Perfluoroarene(AP)interaction between pyrene moiety and OFN were systemically studied.The binary assemblies of PBI/TA and PBI/MA displayed opposite chiroptical properties including CD and CPL signals.Besides,the handedness of CPL was further inverted in ternary assemblies due to the synergistic effect of AP interaction and hydrogen bonds.