富勒烯作为模板剂的碗烯基分子笼构筑的自组装

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

设计合成了四吡啶基取代的碗烯衍生物COPY2.通过核磁研究表明,在模板分子C60或C70存在下,配体COPY2与金属钯分别在室温和55℃下通过自组装形成1∶1分子笼络合物C60/70?COPY2-Pd.当络合物C60?COPY2-Pd与C70等物质的量混合或者络合物C70?COPY2-Pd与C60等物质的量混合于90℃加热48 h后,络合物C60?COPY2-Pd与C70?COPY2-Pd的比例均为4∶1.将配体COPY2与Pd(CH3CN)2Cl2加入等物质的量C60和C70混合物中加热平衡后,络合物C60?COPY2-Pd与C70?COPY2-Pd的比例同样为4∶1.当C60和C70的比例为2∶1时,体系中只生成络合物C60?COPY2-Pd;而当C60和C70的比例为1∶2时,平衡后络合物C60?COPY2-Pd与C70?COPY2-Pd的比例为3.3∶1.这些结果表明,配体COPY2在金属钯存在时对C60络合能力强于C70的络合能力.加入DMAP能够实现络合物解离,释放笼内富勒烯并回收COPY2.因此,配体COPY2可应用于室温下对C60的富集.

A tetrapyridyl substituted corannulene derivative COPY2 was designed and synthesized.Only in the presence of template molecule C60 or C70,COPY2 and palladium could form 1∶1 molecular cage complex C60/70?COPY2-Pd by self-assembly at room temperature and 55℃ respectively.C60 and C70 were used not only as a template for constructing target molecular cages,but also as a stabilizer for molecular cage.When 1.0 equiv.C70 mixed with C60?COPY2-Pd or 1.0 equiv.C60 mixed with C70?COPY2-Pd,the ratio of complex C60?COPY2-Pd to C70?COPY2-Pd is 4∶1 after the mixtures were heated at 90℃ for 48 h,which is consistent with the ratio of COPY2 and Pd(CH3CN)2Cl2 mixed with C60 and C70(1∶1).Only the complex C60?COPY2-Pd was observed when the ratio of C60 to C70 is 2∶1.However,even the ratio of C60 to C70 is 1∶2,complex C60?COPY2-Pd is still the dominant species in the mixture.These results demonstrate that complexing ability of COPY2 with C60 is stronger than that of COPY2 with C70.4-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 C60 at room temperature.