2,2'-Bipyridine Derivatives as Halogen Bond Acceptors in Multicomponent Crystals

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Crystallography

Background:

• Halogen bonding is a key non-covalent interaction in crystal engineering.
• 2,2'-bipyridine derivatives are versatile building blocks for supramolecular assemblies.
• Understanding substituent effects is crucial for designing targeted cocrystal structures.

Purpose of the Study:

• To systematically investigate the halogen bonding potential of various 2,2 -bipyridine derivatives.
• To explore the influence of different substituents on 2,2 -bipyridine on halogen bond formation.
• To synthesize and characterize novel cocrystals using halogen bond donors and 2,2 -bipyridine derivatives.

Main Methods:

• Cocrystal synthesis via liquid-assisted grinding.
• Cocrystal synthesis via solution crystallization.
• Single-crystal X-ray diffraction for structural analysis.

Main Results:

• Eight cocrystals were successfully synthesized from 24 combinations of 2,2 -bipyridine derivatives and halogen bond donors.
• 2,2 -bipyridine derivatives consistently acted as ditopic halogen bond acceptors.
• Dominant interactions observed were I···N and Br···N halogen bonds, with one instance of an I···C(π) interaction.

Conclusions:

• Substituents on 2,2 -bipyridine significantly impact halogen bond interactions and cocrystal formation.
• The study demonstrates the utility of 2,2 -bipyridine derivatives as effective ditopic halogen bond acceptors.
• This research provides valuable insights for the rational design of cocrystals through halogen bonding.