Supramolecular Chiral 2D Materials and Emerging Functions

Abstract

Chiral materials are widely applied in various fields such as enantiomeric separation, asymmetric catalysis, and chiroptical effects, providing stereospecific conditions and environments. Supramolecular concepts to create the chiral materials can provide an insight for emerging chiro-optical properties due to their well-defined scaffolds and the precise functionalization of the surfaces or skeletons. Among the various supramolecular chiral structures, 2D chiral sheet structures are particularly interesting materials because of their extremely high surface area coupled with many unique chemical and physical properties, thereby offering potential for the next generation of functional materials for optically active systems and optoelectronic devices. Nevertheless, relatively limited examples for 2D chiral materials exhibiting specific functionality have been reported because incorporation of molecular chirality into 2D architectures is difficult at the present stage. Here, a brief overview of the recent advances is provided on the construction of chiral supramolecular 2D materials and their functions. The design principles toward 2D chirality and their potential applications are also discussed.

Single‐Layered Chiral Nanosheets with Dual Chiral Void Spaces for Highly Efficient Enantiomer Absorption

“…Stacks of flat objects twisted in one direction overcome this problem due to mirror symmetry breaking, as exemplified in the twist stacking of bilayer graphene . Symmetry breaking by twisting can be applied to macrocycle stacks to generate chiral pores . For example, when facing macrocycle dimers are twisted with respect to each other in one direction, the breaking of mirror symmetry induces the formation of chiral pores .…”

“…[17] Symmetry breaking by twisting can be applied to macrocycle stacks to generate chiral pores. [18] For example, when facing macrocycle dimers are twisted with respect to each other in one direction, the breaking of mirror symmetry induces the formation of chiral pores. [19] The twisted dimeric stacks with a chiral interior laterally associate to form single-layered chiral sheet structures, while layer stacks are prohibited because the 2D aromatic surfaces are covered by the flexible chains.…”

Supramolecular Two‐Dimensional Systems and Their Biological Applications

“…Among diverse self‐assembling modules, aromatic amphiphiles can serve as remarkable candidates for the creation of well‐defined supramolecular 2D structures owing to their rigidity and the π–π stacking of aromatic groups. [ 15–17 ] In self‐assembled 2D structures composed of aromatic amphiphiles, the rigid aromatic segments surrounded by hydrophilic flexible chains can form relatively stable noncovalent interactions in a preferred direction. [ 18 ] Besides, the packing arrangements of aromatic segments can reversibly transform into a different equilibrium state when subjected to subtle environmental changes, demonstrating a distinct adaptive capability of dynamic shape alterations.…”

Sequence Decoding of 1D to 2D Self‐Assembling Cyclic Peptides

“…Two-dimensional (2D) self-assembly is currently attracting great attention as av ersatile platform to access new responsive materials with high surface-to-volume ratios. [1][2][3][4][5] Awidevariety of organic scaffoldsh ave been assembled in 2D by means of all sorts of supramolecular interactions:f rom host-guest chemistry, [6][7][8][9] to metal complexation, [10] electrostaticf orces [11][12][13] and orthogonal polar and hydrophobic interactions. [14][15][16] Supramolecular 2D materials displays tructural adaptability based on their reversible non-covalent bonds,t hus allowing controlled dynamic polymorphism.…”

“…Two‐dimensional (2D) self‐assembly is currently attracting great attention as a versatile platform to access new responsive materials with high surface‐to‐volume ratios [1–5] . A wide variety of organic scaffolds have been assembled in 2D by means of all sorts of supramolecular interactions: from host–guest chemistry, [6–9] to metal complexation, [10] electrostatic forces [11–13] and orthogonal polar and hydrophobic interactions [14–16] .…”