Halogen bonding in the co-crystallization of potentially ditopic diiodotetrafluorobenzene: a powerful tool for constructing multicomponent supramolecular assemblies

Abstract

Halogen bond is emerging as a significant driving force for supramolecular self-assembly, and has aroused great interest during the last two decades. Among the diverse halogen-bonding donors, we take notice of the ability of 1,4-diiodotetrafluorobenzene (1,4-DITFB) to co-crystallize with diverse halogen-bonding acceptors in the range from neutral Lewis bases (nitrogen-containing compounds, N-oxides, chalcogenides, aromatic hydrocarbons and organometallic complexes) to anions (halide ions, thio/selenocyanate ions and tetrahedral oxyanions), leading to a great variety of supramolecular architectures such as discrete assemblies, 1D infinite chain and 2D/3D networks. Some of them act as promising functional materials (for instance, fluorescence, phosphorescence, optical waveguide, laser, nonlinear optics, dielectric and magnetism), and soft materials (e.g. liquid crystal and supramolecular gels). Here we focus on the supramolecular structures of multicomponent complexes and their related physicochemical properties, highlight representative examples, and show clearly the main directions which remain to be developed and improved in this area. From the point of view of crystal engineering and supramolecular chemistry, the complexes summarized here should give helpful information for further design and investigation on the elusive category of halogen-bonding supramolecular functional materials.

Persistent room temperature phosphorescence films based on star-shaped organic emitters

“…32–35 Recently, significant progress has been made in crystal-based metal-free ultralong phosphors. 6,36–42 However, the poor reproducibility, processability, and flexibility of these crystal-based materials will greatly hinder their further development. 14,43–45 Especially, the preparation of their thin films is always a critical and challenging task, while thin films with desirable optical properties are highly desired for many important practical applications.…”

Halogen Bonding in N-Alkyl-3-halogenopyridinium Salts

“…The most commonly used halogen bond donors have traditionally been neutral organic molecules where a halogen atom is bonded to electron-withdrawing molecular residues. Fluorine atoms [55][56][57][58][59][60], nitro and cyano groups [61][62][63][64][65], or C-C triple bond [16,[66][67][68], exhibit an electron withdrawing effect on the halogen atom and consequently increase the positive electrostatic potential (ESP) of the σ-hole of the halogen atom. The same effect can be archived if the halogen atom is bonded to a more electronegative heteroatom such as nitrogen in N-halogenoimides [69][70][71][72][73][74][75][76] or oxygen in organic hypoiodites [77].…”

The Amine Group as Halogen Bond Acceptor in Cocrystals of Aromatic Diamines and Perfluorinated Iodobenzenes

“…The most commonly employed neutral halogen bond donors in crystal engineering to date have been perfluorinated iodobenzenes, namely, 1,2-tetrafluorodiiodobenzene (12tfib), 1,4-tetrafluorodiiodobenzene (14tfib), 1,3-tetrafluorodiiodobenzene (13tfib) and 1,3,5-trifluorotriiodobenzene (135tfib) [37][38][39][40][41][42]. These substances are stable in ambient conditions, soluble in most organic solvents, easy to handle and commercially available.…”