Role of Achiral Nucleobases in Multicomponent Chiral Self‐Assembly: Purine‐Triggered Helix and Chirality Transfer

Abstract

Chiral self‐assembly is a basic process in biological systems, where many chiral biomolecules such as amino acids and sugars play important roles. Achiral nucleobases usually covalently bond to saccharides and play a significant role in the formation of the double helix structure. However, it remains unclear how the achiral nucleobases can function in chiral self‐assembly without the sugar modification. Herein, we have clarified that purine nucleobases could trigger N‐(9‐fluorenylmethox‐ycarbonyl) (Fmoc)‐protected glutamic acid to self‐assemble into helical nanostructures. Moreover, the helical nanostructure could serve as a matrix and transfer the chirality to an achiral fluorescence probe, thioflavin T (ThT). Upon chirality transfer, the ThT showed not only supramolecular chirality but also circular polarized fluorescence (CPL). Without the nucleobase, the self‐assembly processes cannot happen, thus providing an example where achiral molecules played an essential role in the expression and transfer of the chirality.

Achiral substituent- and stoichiometry-controlled inversion of supramolecular chirality and circularly polarized luminescence in ternary co-assemblies

“…[29][30][31][32] In this process, not only the chiral species but also achiral ones could possibly exert significant influence on the regulation of supramolecular chirality. [33][34][35] By using different achiral species for co-assembly, the supramolecular chirality can be inverted in some twocomponent assemblies. 36,37 Typically, when various achiral fluorescent molecules are introduced into two-component assemblies, chirality can be transferred to the luminophores with easily achieved CPL-inversion properties.…”

Multi‐Modal Chiral Superstructures in Self‐Assembled Anthracene‐Terminal Amino Acids with Predictable and Adjustable Chiroptical Activities and Color Evolution

“…[21][22][23][24][25] Over the past five years,l ot of efforts have been put in tuning CPL colors,b oosting the dissymmetry g-factor and expanding potential applications. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] Nevertheless,t he structure-property relationship between chiral assemblies and CPL responses still remain ambiguity. [16,31] Up to now,o nly absolute configuration (enantiomer-resolved) influence on the opposite handedness is confirmed.…”