Halogen Bonding in a Crystalline Sponge

Abstract

Host–guest interactions are the key to the supramolecular chemistry and the further application of the receptors to study the structural details of the small guest molecules. Crystalline sponges as a kind of supramolecular receptor need to be investigated in terms of the binding ability with the guests. We found in this work that one guest with σ-hole donors and another with electron-donating species were separately entrapped in two distinct channels of the host framework via the crystalline sponge method. Halogen bonding and weak hydrogen bonding were detected between the host and the two guests, respectively. The ability of the crystalline sponge to absorb and sort guests of different types was unambiguously confirmed by X-ray crystallography.

Supramolecular aspects of biomolecule interactions in metal–organic frameworks

“…[25,26] The examples in this section have shown how crystallographic techniques are able to identify the interplay of hydrogen bonds and π•••π interactions that are important in localising biological guest molecules within MOF pores. In addition to these interactions, halogen bonds have also been noted in crystalline sponges as a means of anchoring organic iodides [27] and iodine [28,29] and are likely to play a similar role in iodide-containing biomolecules.…”

Applications of the crystalline sponge method and developments of alternative crystalline sponges

“…Several other studies using 1 in the CSM have been published. [76][77][78][79][80][81][82][83][84] While most focus solely on identifying the guest some have analysed host-guest interactions in more detail. In 2016, Carmalt et al 87 studied the uptake of a series of chemically related simple functionalized aromatic guest molecules into the pores of 1 together with an analysis of possible guest-host interactions.…”

Application of Crystalline Matrices for the Structural Determination of Organic Molecules

“…While 1 has been extensively studied and applied, − it has its limitations. The maximum recommended guest size for 1 is 500 MW, and it is incompatible with very basic/nucleophilic moieties and with highly polar solvents that may be needed for sufficient target solubilization.…”