A Self-Assembled Pd(II) Barrel for Binding of Fullerenes and Photosensitization Ability of the Fullerene Encapsulated Barrel.

Fullerene extracts obtained from fullerene shoot lack their real application due to poor solubility in common solvents and difficulty in purification. Their encapsulation in a suitable host is an important approach to address these issues. We present a new Pd 6 barrel ( 1) , which is composed of three 1,4-dihydropyrrolo[3,2-b]pyrrole panels, clipped through six cis -Pd(II) acceptors. Large open windows and cavity make it an efficient host for large guest. Interestingly, favorable interaction between the ligand and fullerene (C 60 and C 70 ) allows the barrel to encapsulate fullerene efficiently. Thorough investigation reveals that barrel 1 has stronger binding affinity towards C 70 over C 60 which leads to the predominant extraction of C 70 from their mixture. Finally, the fullerene encapsulated barrels C 60 1 and C 70 1 were found to be efficient for visible light induced singlet oxygen generation. Such preferential binding of C 70 and photosensitizing ability of C 60 1 and C 70 1 are noteworthy.