Halogen-bonded one-dimensional chains of functionalized ditopic bipyridines co-crystallized with mono-, di-, and triiodofluorobenzenes

A series of halogen-bonded (XB) discrete, one-dimensional (1D) linear and zigzag supramolecular architectures by co-crystalizing a sterically hindered class of homologous ditopic para-xylenes bearing bipyridyl moieties at peripheries with mono-, di-, and triiodofluorobenzene as XB donor components were prepared. The solid-state structures investigated by X-ray diffraction on single crystals show that the molecular geometry of the tectons and halogen bond directionality translates into corresponding XB co-crystals and display a conformational twist at the planes of para-xylene with the adjacent aromatic rings. The bipyridine tectons grafted with photo-responsive azobenzene (–N=N–) side-group, once integrated into the halogen-bonded chains, can be remotely modulated by light, thus being applicable for controlling structure and innovative applications possibilities.