Multifunctional Guest-Hosting Triple-Stranded Helicates: From Anion Recognition to Quantum Information Applications

Area of Science:

• Coordination supramolecular chemistry
• Materials science
• Host/guest chemistry

Background:

• Coordination supramolecular chemistry provides access to multifunctional materials.
• Coordination supramolecular helicates are versatile host structures capable of encapsulating guest molecules.
• Noncovalent interactions (NCIs) stabilize these host/guest assemblies and can induce template effects.

Purpose of the Study:

• To explore the design and applications of triple-stranded helicates for host/guest chemistry.
• To investigate the tunability of helicate cavity properties through ligand design.
• To assess the impact of these supramolecular assemblies in molecular magnetism, quantum technologies, and ion recognition.

Main Methods:

• Synthesis of triple-stranded helicates using metal ions and pyrazolylpyridine/quinoline ligands.
• Encapsulation of various guests, including anions and coordination complexes, within the helicate cavity.
• Characterization of host/guest interactions and resulting material properties (e.g., spin-crossover, single-ion magnet behavior).

Main Results:

• Formation of stable (G@[M2L3])n+ helicates where guests (G) are held by six [N-H···G] hydrogen bonds.
• Demonstration of tunable host properties, including spin-crossover (SCO) and single-ion magnet (SIM) behavior.
• Successful encapsulation of anionic complexes (e.g., [M(ox)3]3-) and observation of enhanced quantum phenomena.

Conclusions:

• Triple-stranded helicates are effective platforms for host/guest chemistry, enabling selective recognition and synergistic multifunctionality.
• Ligand and guest engineering allows fine-tuning of properties for advanced applications.
• These systems show significant potential in molecular magnetism, quantum computing, and sensing.