Atom-Efficient Halogen–Halogen Interactions Assist One‑, Two‑, and Three-Dimensional Molecular Zippers

Unprecedented
multimodal weak interactions are quintessential to
create novel supramolecular topologies. Among the plethora of weak
interactions, halogen–halogen (X···X) interactions
offer innovative possibilities for the design of multidimensional
scaffolds. Herein, we chronicle the state-of-the-art 1D, 2D, and 3D
zipper motifs steered by distinct interhalogen interactions, revealing
the potential of halogen bonding in engineering biomimetic molecular
assemblies. Recurring units of Br4 synthon, framed by type
I and type II atom efficient X···X interactions in
a dibromo­naphthathiazole derivative, 2,4-dibromo-5-ethoxynaphtho­[1,2-d]­thiazole (NTB2), forges the molecular zipper.
On the basis of the semiclassical Marcus theory of charge transport,
the NTB2 zipper assembly displays selective electron transport
along the type II X···X bonded direction. Band structure
analysis classified the crystalline NTB2 as a wide band
gap semiconductor with a band gap of 2.80 eV, respectively. The robustness
of the X···X mediated zipper motif opens up new avenues
in the development of advanced functional materials.