Multicomponent Platinum(II) Cages with Tunable Emission and Amino Acid Sensing

Abstract

The syntheses, characterization, and emission properties of three tetragonal prismatic cages, 4a-4c, constructed from eight 90° Pt(II) acceptors, four linear dipyridyl ligands, and two tetraphenylethene (TPE)-based sodium benzoate ligands, are described. These cages are emissive in dilute solutions due to the metal-coordination-induced partial restriction of intramolecular rotation of their TPE units, while the dipyridyl moieties, which act as the pillars as well as the solvents, strongly influence these emissions. Specifically, cages 4a and 4b, bearing a 4,4'-dipyridine and a 1,2-di(4-pyridyl)ethylene as their pillar parts, respectively, display good emissions in common organic solvents at 485-493 nm that are derived from the TPE units. In contrast, cage 4c, with its BODIPY-based dipyridyl unit, exhibits two emission bands at 462-473 and 540-545 nm, originating from the TPE and BODIPY fluorophores, respectively. Moreover, cage 4b has been employed as a turn-on fluorescent sensor for thiol-containing amino acids via a self-destructive reaction, while the cage can also be regenerated via the addition of Pt(II) acceptors. The studies described herein not only enrich the ongoing research on fluorescent materials but also pave the way to prepare stimuli-responsive supramolecular coordination complexes.

Alanine-Based Chiral Metallogels via Supramolecular Coordination Complex Platforms: Metallogelation Induced Chirality Transfer

“…9–12 During the past few decades, various functional moieties have been appended either on the periphery or at the vertices of a number of discrete supramolecular assemblies. 13–15 Recently, our group reported the efficient preparation of chiral metallacycles and chiral metallacages via the introduction of chiral binaphthy-derived dicarboxylate units.…”

Metal‐Organic Cages for Biomedical Applications

“…Forming discrete rather than extended structures, MOCs possess well‐defined shapes, specific cavities, nano‐scale sizes and symmetrical geometries. During the past decades, many methodologies have also been put forward for the rational design and synthesis of MOCs, such as directional bonding strategy, symmetry interaction strategy, molecular paneling method, weak link strategy, stepwise assembly method, sub‐component self‐assembly approach, etc . In general, for the construction of MOCs (especially those with polyhedral shapes), metal centers (ions or clusters) usually play the role of vertices, while organic ligands serve as edges or faces depending on the binding numbers and sites (Figure ).…”

Hetero‐Multinuclear Co2Pt8 Supramolecular Cages Having D4 Symmetry from Tetrapyridyl Metalloligands

“…Several trigonal and tetragonal prismatic cages have been constructed by selfassembly with various electron acceptors containing metal centers such as ruthenium, palladium, and platinum. 34 However, this strategy has the disadvantages of reversible reactions and unpredictability of the final assembly. 32, 33 We also reported several tetragonal prismatic cages from the combination of complex 1 and di-ruthenium linkers.…”