Corannulene-Adorned Molecular Receptors for Fullerenes Utilizing the π–π Stacking of Curved-Surface Conjugated Carbon Networks. Design, Synthesis and Testing

This brief review outlines recent developments in synthetic methodologies leading to the preparation of efficient molecular receptors for binding fullerenes via the concave–convex π–π stacking of the carbon cages with the corannulene pincers. A simple molecular modelling approach allows for a quick a priori assessment of the affinity of the receptor toward fullerenes. NMR titrations and isothermal titration calorimetry provide the association constants of the receptors with fullerenes in solution, and the X-ray crystal structures of the dimeric and trimeric inclusion complexes exhibit the leading structural motif of stacking of the curved-surface carbon networks in these supramolecular associates. 1 Introduction 2 Bis- and Tris-Corannulene Receptors for Fullerenes 2.1 The Synthetic Tools 2.2 Bis-Corannulene Receptors 2.2.1 Corannulene Twin: A Failure 2.2.2 Buckycatcher I: A Breakthrough 2.3 Other Fullerene Receptors with Corannulene Pincers 2.3.1 Polymeric Materials Containing Corannulene Fragments 2.3.2 Bis-Corannulene Clips with Flexible Tethers 2.4 Is Three Better than Two? Increasing the Number of Pincers 2.4.1 Three Corannulene Pincers on a Cyclotriveratrelene Tether 3 Beyond Buckycatcher I: Engineering the Tethers 3.1 Design 3.2 Buckycatcher II 3.3 Bis-Corannulene Receptors Based on Klärner Tethers – Reaching the Affinity Limits 4 Future Directions: Into the Aqueous Phase and on Solid Supports 5 Summary