Self-Assembled of Corannulene-Based Molecular Cage with Fullerenes as Template

A tetrapyridyl substituted corannulene derivative COPY2 was designed and synthesized. Only in the presence of template molecule C-60 or C-70, COPY2 and palladium could form 1 : 1 molecular cage complex C-60/70 subset of COPY2-Pd by self-assembly at room temperature and 55 V respectively. C-60 and C-70 were used not only as a template for constructing target molecular cages, but also as a stabilizer for molecular cage. When 1.0 equiv. C-70 mixed with C-60 subset of COPY2-Pd or 1.0 equiv. C-60 mixed with C-70 subset of COPY2-Pd, the ratio of complex C-60 subset of COPY2-Pd to C-70 subset of COPY2-Pd is 4 : 1 after the mixtures were heated at 90 degrees C for 48 h, which is consistent with the ratio of COPY2 and Pd(CH3CN)(2)Cl-2 mixed with C-60 and C-70 (1 : 1). Only the complex C-60 subset of COPY2-Pd was observed when the ratio of C-60 to C-70 is 2 : 1. However, even the ratio of C-60 to C-70 is 1 : 2, complex C-60 subset of COPY2-Pd is still the dominant species in the mixture. These results demonstrate that complexing ability of COPY2 with C-60 is stronger than that of COPY2 with C-70. 4-Dimethylaminopyridine (DMAP) was chosen to dissociate the cage so as to release fullerene and ligand. Therefore, the ligand COPY2 could be used to the enrichment of C-60 at room temperature.