Co-Crystallisation of 1,4-Diiodotetrafluorobenzene with Three Different Symmetric Dipyridylacetylacetone Isomers Produces Four Halogen-Bonded Architectures*

The co-crystallisation behaviour of three symmetrical dipyridylacetylacetone ligands (1,3-di(2-pyridyl)-1,3-propane-dione (o-bppdH), 1,3-di(3-pyridyl)-1,3-propanedione (m-bppdH), and 1,3-di(4-pyridyl)-1,3-propanedione (p-bppdH)), with the linear halogen-bond donor 1,4-diiodotetrafluorobenzene (1,4-DITFB) has been investigated. The reaction of these components under ambient conditions in a 1 : 1 stoichiometry produced four halogen-bonded assemblies ([o-bppdH center dot 1,4-DITFB, [m-bppdH center dot 1,4-DITFB], [2(m-bppdH)center dot 1,4-DITFB], and [p-bppdH center dot 1,4-DITFB]). The combination of multiple supramolecular interactions including halogen bonding, hydrogen bonding, and p-stacking produces a range of supramolecular architectures, including one-, two-, and three-dimensional motifs. The crystal structure of m-bppdH is also reported.