Predesigned Cluster-Based Spacers for Versatile Luminescent Metallacages

Abstract

Luminescent metal–organic cages are of great interest in contemporary research; however, their designed synthesis remains challenging. Here, we created metal-cluster-derived spacers, where emissive C 3-symmetric Cu4 clusters have three arms modified by benzene alkynyl ligands, which are terminally functionalized by extensile −COOH and 15-crown-5-ether groups with directional coordination ability. Through vertex orientation, −COOH-functionalized cluster-based spacers coassembled with paddle-wheel Cu(I) x Zn(II)2‑x (COO)3 nodes in 3+3 mode, generating an emissive cubic cage, which subsequently gave another distorted cubic cage by synthetic modification on the nodes. Through face orientation, 15-crown-5-ether-containing cluster-based spacers capturing K+ ions in 3+2 mode produced an octahedral cage whose empty phase showed dual emission peaks, leading to diverse stimuli-responsive photoluminescence. This work provides new design and synthesis strategies for the integration of nodes and spacers based on metal clusters for cage materials as well as prototypes of luminescent metal-cluster cages for important sensing applications.

A dynamic {AuI⋯AuI}-coupling cluster-based coordination capsule for photocatalytic benzylamine oxidation

“…14–18,24 In contrast, polynuclear metal clusters, especially metal–metal bonding cluster assembly motifs, comprehensively enhance the structural diversity, molecular size, and inner cavity of coordination capsules and stimulate more interesting physical and chemical properties. 25–34 In recent years, inter- or intramolecular Au I ⋯Au I bonding interactions, which have similar strengths to hydrogen bonds, 35–41 have been widely utilized in the de novo design and self-assembly of supramolecular aggregates. These aggregates feature various novel structures such as catenanes, 41 polynuclear clusters, 43–46 metallocycles, 47,48 and molecular wires, 49–51 which can potentially be applied in optoelectronic devices and catalytic media.…”

A fluorescence–phosphorescence dual-emissive Cu3(pyrazolate)3 complex with highly tunable emission colours for anticounterfeiting and temperature sensing

“…Widely adjustable emission colours are one of the most concerned aspects for advanced luminescent coordination assemblies, related to a series of intriguing applications, including solid-state lighting, full-colour flat-panel displays, sensors, information encryption, photonic communication, and optical memory. 1–12 To prevent the drawbacks of multiphase emitters ( e.g. , phase separation and colour variation), single-phase coordination materials with separated dual or multiple emission bands whose relative intensities are sensitive to external stimuli ( e.g.…”

Assembly of One-, Two-, and Three-Dimensional Cu(I)-Based Coordination Frameworks for Tunable White Light Emission and Effective Fluorescence Sensing

“…Luminescent coordination polymers (CPs) have received huge attention by virtue of their diverse topologies and broad applications in optics, display, bioimaging, sensing, and detection. − Of particular interest is the family of d 8 /d 10 transition-metal compounds, which is regarded as an emerging class of excellent luminescent solids benefiting from the presence of noncovalent metal···metal interactions in such complexes. − In particular, the copper­(I) halide-based coordination compounds, owing to not only the diverse coordination styles of Cu + (linear, trigonal, and tetrahedral geometry) and halide anions (from μ 2 - to μ 8 -linking) but also their unique photophysical or photochemical properties, have attracted huge interest. − Consequently, great efforts are being made in the pursuit of Cu-X-based (X = I, Br, Cl) networks with diverse structural motifs varying from discrete CuX or CuX 2 , Cu 2 X 2 dimers, Cu 3 X 3 , Cu 4 X 4 , or Cu 6 X 6 clusters, to zigzag [CuX] n or double-stranded [Cu 2 X 2 ] n chains and even to 2D Cu-X-based layers or 3D intricate frameworks. − Thanks to these various building blocks in the self-assembly process, numerous copper­(I) halide-based coordination frameworks have been fabricated in recent years with the assistance of diverse bridging ligands, which have a large possibility to exhibit vivid luminescence rooted in cluster-centered interactions or intracluster metal-halide charge transfer. , For example, Zang and co-workers reported a copper iodide cluster-based metal–organic framework (MOF) scintillator, which presents a high X-ray excited luminescence efficiency and can be used for X-ray flexible imaging …”