Buckycatcher polymer versus fullerene-buckycatcher complex: Which is stronger?

Abstract

The C 60 H 28 buckycatcher (BC) is an excellent host for fullerenes. This receptor features two corannulene pincers which trap C 60 /C 70 via p stacking interactions. Although, the formation of C 60 @C 60 H 28 complexes is readily observed, the dimerization of C 60 H 28 is not a competitive process, even at high concentrations. By means of first principle calculations, we have studied the thermodynamics of the polymerization of BCs and the formation of fullerene complexes. The results obtained with the M06-2X, B97-D, B3LYP-D3BJ, PBE-D2, and PBE-D3 functionals indicated that the interaction energy of (C 60 H 28 ) 2 is larger than the one computed for C 60 @C 60 H 28 , by 8-10 kcal/mol. Because of the greater number of atoms, and due to the presence of more hydrogens, the inclusion of free energy corrections lowers the energetic separation between (C 60 H 28 ) 2 and C 60 @C 60 H 28 , even though the dimer maintains its position as being slightly more bound than that of the C 60 @C 60 H 28 . Our calculations indicated that up to the C 60 H 28 trimer could be formed with a free energy change larger than that corresponding to the dimerization and fullerene complexation processes. Finally, we found that the inversion of the corannulene pincers attached to the cyclooctatetraene core is 2-3 kcal/mol lower than that corresponding to free corannulene. We expect that this work can motivate new investigations that may lead to the observation of C 60 H 28 polymers.

On the estimation of the strength of supramolecular complexes of fullerenes

“…It took only a few years to fullerene receptors to enter to stage after the large scale synthesis of fullerene . Among the various receptors prepared, buckycatchers I/II and Aida's dimeric porphyrins are among the ones which have attracted more attention. In particular, buckycatcher I has become a popular benchmark to develop new density functionals .…”

“…Among the various receptors prepared, buckycatchers I/II and Aida's dimeric porphyrins are among the ones which have attracted more attention. In particular, buckycatcher I has become a popular benchmark to develop new density functionals . Theoretical calculations have made important contributions to the design of new fullerene receptors, and to shed light into the properties of multishell fullerenes, where a fullerene hosts a smaller cage .…”

“…In particular, buckycatcher I has become a popular benchmark to develop new density functionals. [3][4][5][6][7][8][9][10][11][12] Theoretical calculations have made important contributions to the design of new fullerene receptors, [3][4][5][6][7][8][9][10][11][12][13][15][16][17][18][19][20][21][22][23][24][25][26][27][28] and to shed light into the properties of multishell fullerenes, where a fullerene hosts a smaller cage. [29,30] In particular our research group has been interested in the study of new fullerene receptors.…”

“…[29,30] In particular our research group has been interested in the study of new fullerene receptors. [6][7][8][15][16][17][18][19][20] For example, we have modified the pincers of buckycatcher I to dramatically increase the association constant with C 60 . [7] In this line, we also showed that it is not useful to include multiple corannulene pincers are attached to a receptor because they tend to stack.…”

Conformational Analysis of the Supramolecular Complexation of Diaryl-Substituted Tetrathiafulvalene Vinylogues with Fullerenes

“…In 2007, Sygula et al synthesized a corannulene-based molecular pincer, termed “buckycatcher”, which could form an inclusion complex with C 60 fullerene through concave/convex π–π interactions . The binding and charge-transfer properties of the buckycatcher/C 60 complex were later examined by several groups using computational analysis. − …”