Structural Diversity of Host–Guest and Intercalation Complexesof Fullerene C₆₀

Abstract

Pristine fullerene C60 has a fcc structure. Crystallisation of the fullerene in a variety of solvents can lead to inclusion complexes, as well as discrete host–guest complexes in the presence of cavitands and porphyrins, and related molecules. The complexes retain varying degrees of fullerene···fullerene interactions at the van der Waals limit, except in a limited number of cases where the fullerenes are completely shrouded by one or more included/host molecule. Analysis of the fullerene···fullerene interactions in these complexes reveals a diverse structural arrangement of the fullerenes. They can be organised into dimers, single linear columns or zigzag chains, double columns, spectacular fivefold Z‐shaped columnar arrays, hexagonal close‐packed layers, corrugated sheets, honeycomb motifs, non‐close‐packed layers and complex three‐dimensional networks. Disorder of the fullerenes in the solid state is common, although structures with close‐packed planar arrangements of C60 molecules and/or with symmetry matching between the host molecule and the fullerene (two‐, three‐ and fivefold symmetry) tend to have less disorder of the fullerene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Supramolecular Structures and Photoelectronic Properties of the Inclusion Complex of a Cyclic Free‐Base Porphyrin Dimer and C60

“…[26] The tubular structure is formed along the direction of the crystallographic a axis by self-assembly through two kinds of cooperative noncovalent interaction between the cyclic molecules ( Figure 3). One is a pair of complementary C À H···N hydrogen-bonding interactions between the pyrrole b-CH and the nitrogen atoms of the pyridyl groups, with C···N distances of 3.373(6) and 3.473 (5) . The other noncovalent interaction is a weak p-p interaction between the pyridyl groups.…”

Nanofibers of Fullerene C60 through Interplay of Ball‐and‐Socket Supermolecules

“…[18][19][20] Examples of such interplay include the 1:1 complexes between C 60 and cyclotriveratrylene (CTV), [21] and calix [5]arene [22] where the C 60 molecules are packed into continuous zigzag chains; C 60 ···C 60 close contacts vary from 9.90 to 10.20 , with dihedral angles in the chains ranging from 118 to 1728, indicating a transitional packing structure between a linear chain and double-column array. [20] Bowl-shaped calix [5]arenes are effective in controlling the assembly of fullerenes, with dimensionality and curvature complementarity for endo-cavity binding C 60 . [23] Herein we show that p-tBu-calix [5]arene forms a complex with C 60 from toluene, as nanofibers based on the 1:1 supermolecule (C 60 )\(p-tBu-calix [5]arene) [Eq.…”

“…Furthermore, PXRD on a 700 8C treated sample revealed a facecentered cubic (fcc) crystal packing structure, which is the structure of pristine C 60 . [20] Brunauer, Emmett, and Teller (BET) surface area measurements were undertaken for the as-synthesized and isothermal hold products ( Figure 9). Interestingly, there is a 45-fold increase in the surface area exhibited for the product obtained at 800 8C in relation to the as-synthesized product.…”

Supramolecular Assemblies of Tripodal Porphyrin Hosts and C60

“…[24] In 3, all centroid-to-centroid distances are relatively long, suggesting the absence of such interaction. For 4, the two symmetry-related fullerenes confined as a pair for interactions in the asymmetric unit show close contact for fullerene-fullerene interactions.…”

“…This is characterized by the distances between the best-fit plane of porphyrin units and the surface of the carbon sphere (2.70-2.93 ) which are significantly less than the sum of the van der Waals radii (3.09 ). [24] Combined with the doming or ruffling of all the porphyrin planes, this provides evidence of the van der Waals nature of the attractive forces, where such geometrical distortion of the planar surfaces has often been regarded as the result of maximizing the strength of attractions by wrapping fullerenes more effectively.…”