Hydrogen bonded supramolecular capsules with functionalized interiors: the controlled orientation of included guests

Abstract

This tutorial review aims to present and describe selected examples of still quite rare endo-functionalized supramolecular capsules. Only capsules assembled through the use of neutral or polar hydrogen bonding interactions are covered. The ability of these capsules to orient and control the position of the encapsulated guest molecules represents their stand-out feature. Thus, the way in which guests interact with the functionalized interior of the capsules is discussed in detail. Several of the described capsular assemblies display chiral architectures. The manner in which chirality is manifested in these assemblies is far from trivial. For this reason, we also offer explanations of the chiral features expressed by the relevant capsules and their encapsulation complexes.

Selective C70 encapsulation by a robust octameric nanospheroid held together by 48 cooperative hydrogen bonds

“…The continuing development of supramolecular chemistry and the improved understanding of its underlying assembly processes have led to the synthesis of increasingly complex and sophisticated three-dimensional structures such as nanotubes1, cages23 and capsules456. There is a close relationship between the structure of a given architecture and its functionality, as in natural systems, and chemists have exploited this in the design of functional structures that possess desirable properties and that may be used inter alia to build molecular machines7.…”

Halogen-Bonded Co-Crystals of Aromatic N-oxides: Polydentate Acceptors for Halogen and Hydrogen Bonds

“…Besides being valuable synthetic intermediates, the dipolar neutral N⁺−O − group exhibits a push-pull property towards aromatic rings, enabling it to undergo both electrophilic and nucleophilic substitution reactions, categorizing these compounds as promising building blocks in supramolecular chemistry [26,27]. Electron-donating and electron-withdrawing substituents on aromatic ring invoke different hybridization states on oxygen in the N−O group [28,29], allowing for tuning of its complexation behaviour towards metals [30,31].…”

Noncovalent interactions between O6‐corona[6]arene nanorings and fullerenes C60 and C70: atypical ring ball‐shaped host‐guest systems

“…Especially, for a nanoscale system, host‐guest interaction may result in novel nanohybrid with new properties and unique functions, which is maybe very different from the individual host or guest molecule . The well‐designed host‐guest complexes have been used to construct various supramolecular function systems, such as novel host systems that can reversibly capture and release guest molecules in a controllable manner …”