Anion-Coordination-Driven Assembly.

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Hierarchical assembly in supramolecular chemistry relies on covalent and noncovalent interactions.
• Metal-coordination-driven assembly is a well-established strategy, but anion coordination chemistry offers a metal-free alternative.
• Anions exhibit 'dual valencies,' enabling them to act as coordination centers through hydrogen bonding.

Purpose of the Study:

• To present anion-coordination-driven assembly (ACDA) as a novel strategy for supramolecular architecture.
• To highlight the construction of aniono supramolecular structures, including triple helicates and tetrahedral cages.
• To explore the functionalization of these systems for applications in guest inclusion, catalysis, and molecular devices.

Main Methods:

• Design of oligourea ligands capable of coordinating with anions, primarily phosphate.
• Utilizing hydrogen bonding interactions as the primary driving force for assembly.
• Investigating structural transformations and functionalization of the resulting supramolecular architectures.

Main Results:

• Successful construction of discrete aniono supramolecular structures, such as triple helicates and tetrahedral cages.
• Demonstration of metal-free systems assembled via multiple hydrogen bonds (dozens to nearly 100).
• Exhibition of mild assembly/disassembly conditions and flexible structures suitable for adaptive guest inclusion.

Conclusions:

• ACDA is a powerful and versatile strategy for fabricating novel anion-based supramolecular systems.
• The metal-free nature of these assemblies offers advantages in terms of flexibility and mild processing.
• Aniono supramolecular systems hold significant potential for applications in areas like supramolecular chirality, catalysis, and energy storage.