Multicomponent Self‐Assembly of Metallo‐Supramolecular Macrocycles and Cages through Dynamic Heteroleptic Terpyridine Complexation

Abstract

Spontaneous formation of the heteroleptic cadmium(II) bis(terpyridine) complex under ambient conditions can be achieved by a combination of 6,6''-di(2,6-dimethoxylphenyl)-substituted and unsubstituted terpyridine-based ligands. Building on this dynamic heteroleptic complexation, diverse metallo-supramolecular macrocycles and cages were readily assembled in quantitative yields from the predesigned multicomponent systems. The complementary ligation reinforced self-recognition to facilitate the shape-dependent self-sorting of a four-component dynamic library into two well-defined parallelograms. In addition, the subtle lability difference between homoleptic and heteroleptic complexes led to the site-selective Cd -Zn transmetalation in the Sierpiński triangle. Facile construction of a dodecanuclear tetrahedral metallocage was also realized by using two self-recognizable tritopic building blocks. The photophysical study of the metallo-supramolecules assembled from the d metal ions revealed intense ligand-based photoluminescence in solution. The self-assembly strategy described here provides an efficient methodology for building pre-programmable, sophisticated supramolecular architectures furnished with photoactivity.

Reaction Monitoring and Structural Characterisation of Coordination Driven Self-Assembled Systems by Ion Mobility-Mass Spectrometry

“…Other recent investigations into self-sorting have utilised IMS-MS to varying degrees. Some, such as investigations of ligand spacer length effects on product heteroleptic macrocycles and cages, use IMS-MS to show the clear separation by both IMS and MS of the sorted assemblies ( Wang et al, 2018c ; He et al, 2020 ). In these studies IMS-MS is effective because the spacer length change creates clear structural and m/z differences that can be identified.…”

From Dendrimers to Macrocycles: 80 Years George R. Newkome—Milestones of a Gentleman Scientist

“…One recent example is Prof. Yi‐Tsu Chan, who is a professor in Taiwan. He focused on the design of new supramolecular assemblies using metal–ligand interactions …”

Conformational Regulation of Multivalent Terpyridine Ligands for Self-Assembly of Heteroleptic Metallo-Supramolecules

“…Aiming to further enhance geometrical diversity and complexity of assemblies, comprehension of self-assembly mechanisms and development of high-fidelity molecular recognition tools are essential for preventing the formation of undesired products in a multicomponent system. Hence, several self-selective coordination strategies have been developed for mono-, bi-, and tridentate ligands to fulfill the requirements. Among them, a variety of multivalent 2,2′:6′,2″-terpyridine (tpy)-based ligands can be obtained by palladium-catalyzed cross-coupling reactions and serve as subcomponents for self-assembly of giant metallo-supramolecules .…”