Coordination‐Driven Terpyridine‐Based Twisted Prisms with Tunable Emissions and Hierarchical Self‐Assembly Properties

Abstract

Tunable fluorescence emission materials play a critical role in many fields such as biology and chemistry. With respect to metallo‐supramolecular assemblies, the construction of 3D tunable‐fluorescent supramolecular assemblies with 2,2′:6′,2″‐terpyridine (tpy) is still in its infancy. In this study, two luminous 3D supramolecular prisms self‐assembled with two terpyridine‐based tetraphenylethylene (TPE) ligands and metal Zn(II) are prepared, and the influence of hydrophobic alkyl chains on tunable fluorescence is further explored. By exploiting hydrophobic properties, the prism SA exhibits tunable visible‐light emission in the molecular‐aggregated state. Moreover, SA forms left‐hand and right‐hand helical nanofibers by hierarchical self‐assembly. However, the prism SB without hydrophobic chains does not exhibit tunable fluorescence emission, and only random spherical aggregates after hierarchical self‐assembly are formed. This study can aid to further strengthen the understanding about the effect of hydrophobic segments on photophysical properties and hierarchical self‐assembly of discrete supramolecular architectures.

A Highly Luminescent Metallo-Supramolecular Radical Cage

“…Compared with other metallo-complexes, 3D metallo-cages with well-defined geometries and rigid topological architectures could restrict the conformations of organic motifs. − This constraint has led to investigations into their luminescent properties in various fields, including magnetic resonance imaging, tunable and high emission, , circularly polarized luminescence, − and aggregation induced emission (AIE), , by combining diverse functional groups. The study of metal-radical cages incorporating luminescent radical units will inject new vitality to the interdisciplinary frontier of metallo-supramolecular chemistry and luminescent radical materials …”

Coordination-Induced Conformational Control Enables Highly Luminescent Metallo-Cages

“…Coordination-driven self-assembly is a powerful and straightforward approach for synthesizing supramolecular architectures because of the definite directionality, predictable nature of metal–ligand coordination interactions, as well as moderate bond energies (15–25 kcal/mol) of the metal–ligand coordination interactions. , Therefore, a series of discrete emissive metal–organic complexes (MOCs) with well-defined sizes and shapes, ranging from metallo-macrocycles − to metallo-cages − have been successfully prepared by introducing different chromophores into predesigned ligands. Among these MOCs, metallo-cages exhibited greater degrees of restricted free rotation of chemical groups and are better at exploiting their luminescence properties than metallo-macrocycles …”

2-(((4-([2,2′:6′,2″-Terpyridin]-4′-yl)phenyl)imino)methyl)-6-methoxyphenol

“…The functionalization of 2,2 :6 ,2 -terpyridine (tpy) has attracted increasing attention in the past few decades on account of the distinguished electrochemical and photophysical properties [1][2][3][4]. Terpyridine derivatives have been broadly applied to ligands, organic optoelectronic materials, and supermolecular materials due to their superior metalbinding ability, π-stacking ability, and strong hydrogen bond interaction [5][6][7][8][9][10]. Particularly, terpyridine-containing imine structure gaining researchers' insight into designing fluorescent and colorimetric chemosensors because of the peculiar coordination properties encompassed by the tridentate ligand feature of tpy and the strong binding affinity of C=N bond in the imine group [11][12][13].…”