Chiral Cyclic Hypervalent Iodine(III) for Halogen Bonding-Mediated Dimerization and Modulable Chirality Induction in...

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Halogen bonding is crucial for constructing functional materials.
• Solvation significantly disrupts halogen bonding in solution-phase synthesis.
• Developing solution-phase methods for chiral materials is challenging.

Purpose of the Study:

• To enable solution-phase construction of chiral functional materials via halogen bonding.
• To overcome solvation challenges in halogen bond-mediated synthesis.
• To create discrete-state chiroptical materials with tunable properties.

Main Methods:

• Introduction of a chiral site into a cyclic hypervalent iodine(III) scaffold (I(III)).
• Assembly of I(III) into cationic antielectrostatic halogen-bonded dimers.
• Characterization of I(III) binding affinity and chirality induction in various solvents.

Main Results:

• Stable halogen-bonded dimers formed via quadrupled halogen and hydrogen bonding networks.
• Strong binding affinity (K_a ~10⁴ M^-1) of I(III) to neutral and anionic acceptors.
• Efficient chirality induction in ground and excited states, leading to tunable chiroptical properties.
• Solvent-responsive, mirror-image chiroptical properties observed in different solvents.
• Demonstrated adaptability for chirality induction across diverse systems.
• Achieved full-color circularly polarized luminescence.

Conclusions:

• The developed method facilitates solution-phase construction of chiral functional materials using halogen bonding.
• The I(III) scaffold enables robust chirality induction with tunable properties.
• This approach broadens the scope of halogen bond-mediated material synthesis and applications in chiroptical devices.