Self-Complementary Dimers Based on Zwitterionic Halogen Bond Donors

Area of Science:

• Supramolecular Chemistry
• Crystal Engineering
• Organic Chemistry

Background:

• Halogen bonding is a key interaction in crystal engineering.
• Multipoint halogen bonding motifs, especially self-complementary ones, are scarce.
• Zwitterionic systems offer unique possibilities for designing halogen bond donors and acceptors.

Purpose of the Study:

• To design and synthesize the first isolated homodimers based on a zwitterionic halogen bond donor.
• To explore the potential of iodolium and sulfonate groups in creating self-complementary halogen bonding systems.
• To investigate the structural and binding properties of these novel supramolecular assemblies.

Main Methods:

• Synthesis of zwitterionic compounds featuring an iodolium core and a sulfonate group.
• Crystallographic analysis to determine the structure of the isolated homodimers.
• Spectroscopic and computational methods to characterize the halogen bonding interactions.

Main Results:

• Successful formation of the first isolated homodimers utilizing a zwitterionic halogen bond donor.
• Strongly bound dimers were observed with halogen bond distances up to 2.73 Å.
• Optimization from carboxylate to sulfonate variants improved solubility and system stability.

Conclusions:

• The developed zwitterionic iodolium-sulfonate motif represents a novel approach to self-complementary halogen bonding.
• These homodimers demonstrate the potential for designing advanced materials with predictable multipoint interactions.
• This work lays the foundation for developing new halogen-bonding-based linkers for various applications.