Construction of Halogen-Bonded Organic Frameworks (XOFs) as Novel Efficient Iodinating Agents

Abstract

The structural diversity and the various applications of organic frameworks have attracted much attention in recent years. Recently, halogen-bonded organic frameworks (XOFs) became a novel member of these materials, thereby facilitating the exploration of the interesting structures as well as functions. Here we present two types of [N···I+···N] connected XOFs (XOF-TPy and XOF-TPEB) with two tridentate ligands as building blocks. XOF-TPy and XOF-TPEB were characterized by 1H NMR, UV–vis, X-ray photoelectron spectroscopy (XPS), IR, SEM, and HR-TEM. Two-dimensional (2D) structural models were established based on powder X-ray diffraction (PXRD) data and theoretical simulations. Further experiment showed that these XOFs were excellent iodinating agents for the substituted arylboronic acids with either the electron-donating or electron-withdrawing groups upon heating without any catalyst. This research not only brings further understanding to the XOFs but also extends the applications of XOFs.

Structure and Bonding of Halonium Compounds

“…The bonding in halonium ions (X = Cl, Br, and I) leads to a hypercoordinated system. These stable − noncovalent complexes with short interatomic distances, in which the central atom exceeds the octet rule, have attracted interest due to their applicability as synthetic reagents , and in the design of complex supramolecular synthons ,− and two-dimensional (2D) halogen-bonded organic framework (XOF) materials. − The nature of the interaction in halonium cations can be described in terms of orbital and electrostatic contributions, − with smaller contribution of dispersion forces . According to the Pimentel–Rundle model, − the halonium cation interacts simultaneously with two Lewis bases by accepting electrons through both lobes of its empty p-orbital.…”

A zinc porphyrin-based halogen-bonded organic framework with the heavy atom effect as a highly efficient photocatalyst for oxidative coupling of amines

“…The calculated Brunauer-Emmett-Teller (BET) surface area was 10.83 m 2 g −1 , indicating low porosity, which might originate from the large size of counterions (BF 4 − ) blocking the pores. [36][37][38]51 Powder X-ray diffraction (PXRD) experiments were performed to elucidate the crystal structure of XOF-ZnTPP (Fig. 1b), and the possible crystal models were meticulously simulated using the Materials Studio soware package.…”

“…[27][28][29] Notably, the [N/ I + /N] halogen bonds have garnered substantial attention in the realm of supramolecular assemblies, and are applied in the construction of discrete supramolecular structures, such as supramolecular capsules, [30][31][32][33] macrocyclic complexes, 34 and helicases. 35 Moreover, our group has previously achieved the successful fabrication of halogen-bonded organic frameworks (XOFs) through [N/I + /N] halogen bonds, [36][37][38][39] underscoring the robust utility of [N/I + /N] halogen bonds as a robust tool for the innovative design of organic frameworks. What's more, comprehending the impact of the special connection knots on the properties of the new XOFs is pivotal in unlocking their functionalities and exploring their potential applications.…”

Supramolecular axial chirality in [N–I–N]+-type halogen bonded dimers

“…The existence of I 3d spectrum indicates the generation of I + species based on the previous reports. 43,44 Fourier transform infrared spectroscopy (FT-IR) reects the variations in bond information. In Fig.…”