Catalytic reactions within the cavity of coordination cages

Abstract

This review summarizes recent developments of coordination cages catalysis across three key approaches: (1) cavity promoted reactions, (2) embedding of active sites in the structure of the cage, and (3) encapsulation of catalysts within the cage.

Metal‐Organic Frameworks and Metal‐Organic Cages – A Perspective

“…As with MOFs, there has been great interest in employing MOCs for catalysis. Indeed catalysis within MOCs [139] and catalysis within confined systems more generally [140] have both been recently reviewed highlighting the breadth of this field. MOC-based strategies involve bringing reactants into closer proximity (benefitting reactions such as Diels-Alder cycloadditions [25a,141] ), the enforcement of guests to adopt more compact conformations (promoting reactions such as the aza-Cope rearrangement [142] and Nazarov cyclization [143] ) and increasing the local concentration of the catalyst in the cavity to levels far higher than the overall concentration in solution.…”

Catalysis of an Aldol Condensation Using a Coordination Cage

“…The use of self-assembled molecular containers such as coordination cages as catalysts for reactions that occur in the central cavity has provided some remarkable examples of synthetic hosts providing enzyme-like levels of the rate acceleration of reactions. The range of reactions that has been shown to be catalysed is now extensive [1][2][3][4][5][6][7][8][9][10].…”

Uranyl Ion Complexes of Polycarboxylates: Steps towards Isolated Photoactive Cavities

“…Intensive research over the past few decades has been devoted to the synthesis of crystalline cavity-containing, framework, and coordination polymer species of a porous nature suited to the storage, immobilisation, sensing, or reaction of a wide variety of substrates of environmental and economic importance [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. (The references cited here are a somewhat eclectic selection intended to illustrate the range of chemistry involved, rather than to be comprehensive, which is far from the case.)…”

“…While metal ions clearly have a fundamental role in determining the structure of these materials, of equal importance is that they endow the solids with functionality specific to the given metal ion. One such function is that of photoactivity, a property which may have various manifestations [2,8], but which in the case of uranium(VI) as uranyl ion, UO 2 2+ , derivatives, is anticipated to be that of photo-oxidation catalysis, long known in their solution chemistry [20][21][22]. Although photocatalysis by metal-organic framework (MOF) systems in particular could be described in 2017 as a "largely unexplored field" [23], it has rapidly become a popular area of study [24].…”