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

In this work, we present a systematic study of the halogen bonding potential of different 2,2′-bipyridine derivatives in the synthesis of cocrystals by using selected perfluorinated iodobenzenes and N-haloimides as halogen bond donors. These halogen bond acceptor molecules were chosen to explore how different substituents on 2,2′-bipyridine affect halogen bond formation. Out of 24 combinations, we obtained only 8 cocrystals by using two methods, liquid-assisted grinding and crystallization from the solution. Of those 8 cocrystals, one has already been described in the literature. As expected, structural data revealed that 2,2′-bipyridine derivatives act as ditopic halogen bond acceptors in all structures. Dominant interactions in 7 of the cocrystals are I···N or Br···N halogen bonds, while in the one remaining cocrystal it is the I···C(π) halogen bond.