Halogen bonding in supramolecular synthesis.

Supramolecular synthesis is typically limited to one-pot reactions because of the reversibility of non-covalent bonds, and to overcome this restriction we need to be able to rank the relative structural importance of such interactions and build synthetic methods to utilize synthons which can operate side-by-side without interference. Halogen bonds have characteristics (strength and directionality) which potentially make them prime candidates as critical components of effective, transferable, and versatile supramolecular synthetic strategies. In this chapter, several halogen-bond driven crystal engineering strategies for the assembly of specific architectures in molecular solids are described in detail, and the utility of halogen bonds for the synthesis of co-crystals are addressed. Finally, the structural compatibility or competition between of halogen- and hydrogen bonds in the context of supramolecular synthesis are examined.