A Polyaromatic Nano-nest for Hosting Fullerenes C₆₀ and C₇₀

Abstract

A "Janus" type of hexa- cata-hexabenzocoronene with three triptyceno subunits fused symmetrically on the periphery of coronene has been synthesized using a covalent self-assembly strategy. The triptyceno subunits form a nanosized nest on one side of the aromatic plane with space-matching fullerenes such as C and C to afford shape-complementary supramolecular complexes. The formation of the complexes in solution was confirmed by H NMR and fluorescence titration. Four complexes with C or C were obtained and studied by single-crystal X-ray diffraction analysis. In the crystal structure, the host shows a proper tunability to adjust its conformation in accordance with the shape of the guest. The different stoichiometric ratios and various stacking patterns of the complexes suggest the diversity of this nonplanar polyaromatic host in complexation with fullerenes.

The Green Box: An Electronically Versatile Perylene Diimide Macrocyclic Host for Fullerenes

“…Furthermore, the closest rings of C 60 facing the PDI panels are 3.44 and 3.59 Å between their centroids and the plane of the central six-membered ring (PDI C6 plane) in the top and bottom PDI units, respectively (C 60 ···PDI C6 distance). These intermolecular distances are consistent with the existence of π–π aromatic stacking interactions between the convex C 60 host and the concave surfaces of the PDI units. − In agreement with NMR data, the spatial disposition of the pyrrolidine substituents allows several C–H protons to establish C–H···π interactions with C 60 , with C–H pyr ···C 60 distances ranging from 2.56 to 3.36 Å (Table S10.2).…”

Radially π-Extended Pyrrole-Fused Azacoronene: A Series of Crystal Structures of HPHAC with Various Oxidation States

“…The crystals were obtained from the vapor-diffusion method with anisole and 2-propanol, in which two crystallographically independent structures exist in the unit cell. In both structures, steric congestion at the peripheral acenaphthylene moieties containing t Bu groups forced the outer rings to flip up and down in an alternating manner, a Janus “double-concave” π-structure, as expected. ,, The bowl depths for the two concave structures, defined as the distance between the centroid of the central benzene and the centroid of the 3,4-positions in the three acenaphthopyrrole skeletons, are 2.26 and 2.46 Å (Figure S4). In the packing structure, an intermolecular interaction was observed via CH−π interactions between the hydrogens of the t Bu groups and the acenaphthylene moieties (Figure S5).…”

“…In this study, radially π-extended HPHAC 2 was designed and synthesized using 2,5-di- tert -butyl-8 H -acenaphtho­[1,2- c ]­pyrrole ( 3 ) as a key unit. As was seen in our cyclo­[ n ]­pyrroles ( n = 8 or 10), acenaphthopyrrole 3 is expected to induce a π-extension and an alternative conformation because of the acenaphthylene moieties with bulky t Bu groups, leading to a Janus “double-concave” π-structure . Recently, Stępień’s group has reported the crystal structure of an HPHAC derivative with highly solvated organic clathrates owing to its enlarged and ruffled π-structure …”

Coronenes, Benzocoronenes and Beyond: Modern Aspects of Their Syntheses, Properties, and Applications

“…The cata ‐HBCs were reported to act as a nano‐nest for hosting fullerenes C 60 and C 70 molecules [218] . While substitution on the core was found to affect the semiconducting properties of HBCs, [219] some post‐deposition methods were also used to improve field‐effect mobilities [220] .…”