Reversible reduction drives anion ejection and C₆₀ binding within an FeII4L₆ cage

Abstract

FeII4L6 cage 1 binds anionic guests but not neutral guests. In its reduced form, the cage can bind neutral C60. Reduction and oxidation of the cage could thus be used as a stimulus to control the uptake and release of both neutral and charged guests.

Cavity-based applications of metallo-supramolecular coordination cages (MSCCs)

“…Fe from organic to aqueous solution facilitated the process of guest release. 50 The removal of environmental pollutants and the recovery and purification of valuable chemicals by selective anion extraction is a useful tool. In 2018 Nitschke's group reported the use of an Fe II 4 L 4 , II f Fe cage ( Fig.…”

Oxidation triggers guest dissociation during reorganization of an FeII4L6twisted parallelogram

“…We thus envisioned that the incorporation of metallocene ligands into supramolecular capsules with octahedral metal ion vertices could enable the formation of low-symmetry products. Metallocenes are furthermore redox-active, enabling potential stimuli-responsive behavior 42,[45][46][47][48][49][50][51][52][53] that may be used for different host-guest interactions, 45,47,54 such as redox-triggered guest ejection or structural reconguration. 55,56…”

Naphthalene diimide- and perylene diimide-based supramolecular cages

“…Considering the redox-active properties of NDI, at the same year, Nitschke and co-workers reported the synthesis of a NDIbased cage with redox-responsive guest uptake and release behaviour. 17 Notably, the addition of excess reductant Cp 2 Co into cage 19 led to the formation of precipitation resulting from charge neutralization (the negatively charged NDI panels were compensable to the cationic charges of Zn 2+ vertices), which hampered the further study in solution. Thus, quaternary ammonium-functionalized NDI ligand 23 in place of ligand 18 was prepared to construct the new NDI cage 24 (Fig.…”