Synthesis and Applications of Endohedrally Functionalized Metal‐Ligand Cage Complexes

Abstract

Self‐assembled cages have garnered wide‐spread interest as supramolecular hosts. Their abilities may be augmented through the installation of functional groups on the interior of the cage. This article highlights recent advances in the applications of endohedral functionalization in control of overall self‐assembly, molecular recognition and reactivity, with an emphasis on installing functionalization that enables biomimetic catalysis.

How to not build a cage: endohedral functionalization of polyoxometalate-based metal–organic polyhedra

“…Although the rational design of MOPs has been widely explored and immensely successful, introducing functionalities into the cages remains challenging. 8 Unlike metal–organic frameworks, many MOP cages are built with single-metal nodes, 9–16 which are often coordinatively saturated and thus incapable of binding to additional functional groups. It should be noted, though, there are a handful of reports 17–21 taking advantage of the open, axial binding sites of metal porphyrins to install endo functional groups or to trap guest molecules inside MOP cavities.…”

Self-assembly of a water-soluble endohedrally functionalized coordination cage including polar guests

“…3,5,6,7,8 The inclusion of polar guests requires the functionalization of the CCs' cavities with polar groups. 9,10 However, the extensive use of aromatic panels in shaping the cavity makes this endeavour synthetically difficult. Fujita introduced a strategy to generate spherical [L24•Pd12] 24+ CCs containing 24 inwardly-directed functional groups.…”

Size- and Shape-Selective Catalysis with a Functionalized Self-Assembled Cage Host

“…The scope of reactivity in self-assembled synthetic hosts can be greatly expanded by introducing internally oriented functional groups to the host scaffold . This concept is inspired by enzyme active sites, which show exquisite reaction control in a tight binding pocket .…”

“…The scope of reactivity in self-assembled synthetic hosts can be greatly expanded by introducing internally oriented functional groups to the host scaffold. 1 This concept is inspired by enzyme active sites, which show exquisite reaction control in a tight binding pocket. 2 The internal cavities in synthetic hosts cannot show the same specific size and shape matching to substrates as enzymes, so their effects on substrate reactivity are far more variable.…”