Synthesis of C₆₀/[10]CPP‐Catenanes by Regioselective, Nanocapsule‐Templated Bingel Bis‐Addition

Abstract

The addition of two unsymmetric malonate esters to the Buckminster fullerene C60 can lead to 22 spectroscopically distinguishable isomeric products and therefore represents a formidable synthesis challenge. In this work, we achieve 87% selectivity for the formation of a single (in,out‐trans‐3) isomer by combining three approaches: (i) we use a starting material, in which the two malonates are covalently connected (tether approach); (ii) we form the strong supramolecular complex of C60 with the shape‐persistent [10]CPP macrocycle (template approach) and (iii) we embed this complex further within a self‐assembled nanocapsule (shadow mask approach). Variation of the spacer chain shed light on the limitations of the approach and the ring dynamics in the unusual [2]catenanes were studied in silico with atomistic resolution. This work significantly widens the scope of mechanically interlocked architectures comprising cycloparaphenylenes (CPP).

Recent advances in supramolecular fullerene chemistry

“…3) for the trans-3 selective bisfunctionalization of C 60 to achieve the synthesis of a new type of [2]catenane 74. 414 These catenanes comprise a [10]CPP ring that is mechanically interlocked with a larger macrocycle that is formed in the final step of the synthetic route by Bingel bisaddition to C 60 . Because the malonate esters (73) are unsymmetric, this reaction could lead to an astonishingly complex reaction mixture with up to 22 spectroscopically distinguishable isomeric products.…”

Cycloparaphenylene-based [2]catenanes: interlocking the carbon nanohoops

“…To not only deal with such selective issues for CPP-based [2]catenane synthesis but also develop new synthetic methodologies for fullerene bis-adducts, based on their previous excellent work on the chemo- and regio-selective bis-functionalization of C 60 based on a three-shell matryoshka-like complex, 11 Ribas and von Delius et al recently successfully realized the synthesis of a series of novel CPP-based [2]catenanes through the regioselective Bingel bis-addition of encapsulated C 60 . 12…”

Host–guest complexes of perylene bisimide-based metallacage and fullerenes for efficient photoinduced charge separation

“…20–22 This powerful tool allows for precise construction of supramolecular complexes, such as metal–organic cages or metallacages, in various shapes and sizes. 23,24 Metal–organic cages are molecular assemblies of organic ligands coordinated with either metal cations or metal oxide clusters of different nuclearities, resulting in architectures with inherent porosity. Similar to other macrocyclic compounds, metal–organic cages are capable of binding various organic guests.…”