Controlled Construction of Heteroleptic [Pd<sub>2</sub>(L<sup>A</sup>)<sub>2</sub>(L<sup>B</sup>)(L<sup>C</sup>)]<sup>4+</sup>Cages: A Facile Approach for Site‐Selective endo‐Functionalization of Supramolecular Cavities
Yan Liu, Shou‐Heng Liao, Wen‐Tao Dai, Qixia Bai, Shuai Lü, Heng Wang, Xiaopeng Li, Zhe Zhang, Pingshan Wang, Wei Lu, Qi Zhang
Abstract
Abstract Construction of supramolecular structures with internal functionalities is a promising approach to build enzyme‐like cavities. The endo‐functionalized [Pd 12 L 24 ] and [Pd 2 L 4 ] coordination cages represent the most successful systems in this regard. However, these systems mainly contain one type of endo‐moiety. We herein provide a solution for the controlled endo‐functionalization of [Pd 2 L 4 ] cages. Site‐selective introduction of the endo‐functional group was achieved through the formation of heteroleptic [Pd 2 ( L A ) 2 ( L B )( L C )] cages. Using two orthogonal steric control elements is the key for the selective formation of the hetero‐assemblies. We demonstrated the construction of two hetero‐cages with a single internal functional group as well as a hetero‐cage with two distinct endohedral functionalities. The endo‐functionalized hetero‐cages bound sulfonate guests with fast‐exchange dynamics. This strategy provides a new solution for the controlled endo‐functionalization of supramolecular cavities.