Supramolecular networks by imine halogen bonding

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Crystallography

Background:

• Porous organic cages (POCs) are versatile molecular platforms with tunable structures.
• Imine groups within POCs can act as halogen bond acceptors.
• Halogen bonding is a key non-covalent interaction for constructing ordered materials.

Purpose of the Study:

• To investigate the formation of halogen-bonded frameworks using imine-functionalized POCs.
• To explore the use of different halogen bond donors with POC acceptors.
• To characterize the resulting solid-state structures and bonding interactions.

Main Methods:

• Synthesis of imine-containing porous organic cages.
• Crystallization of POCs with electron-poor halogen bond donors.
• Single-crystal X-ray diffraction analysis.
• Plane-wave Density Functional Theory (DFT) calculations.
• Quantum Theory of Atoms in Molecules (QTAIM) analysis.

Main Results:

• Formation of stable halogen-bonded frameworks between imine POCs and halogen bond donors.
• Elucidation of four distinct solid-state structures via X-ray crystallography.
• Confirmation of halogen bonding interactions within the crystal lattices using DFT and QTAIM analyses.
• Successful synthesis of frameworks through both solution-based and mechanochemical methods.

Conclusions:

• Imine groups in POCs effectively act as halogen bond acceptors, enabling the construction of extended networks.
• The combination of POCs and halogen bond donors offers a viable route to novel supramolecular materials.
• Both solution and mechanochemical approaches are effective for synthesizing these halogen-bonded frameworks.