Luminescent Au(I)/Cu(I) Alkynyl Clusters with an Ethynyl Steroid and Related Aliphatic Ligands: An Octanuclear Au4Cu4 Cluster and Luminescence Polymorphism in Au3Cu2 Clusters

Terpyridine isomerism as a tool for tuning red-to-NIR emissive properties in heteronuclear gold(I)-thallium(I) complexes

The polymeric linear chain [AuTl(C6Cl5)2]n reacts with three terpyridine-type ligands substituted with thiophene groups containing N-donor centres in different relative positions (L1, L2 and L3), leading to the Au(I)/Tl(I) complexes [AuTl(C6Cl5)2(L1)]n (1), [{AuTl(C6Cl5)2}2(L2)]n (2) and [AuTl(C6Cl5)2(L3)]n (3). X-Ray diffraction studies reveal that L1 acts as a chelate, while L2 and L3 act as bridging ligands, resulting in different coordination indexes for the thallium(I) centre. These structural differences strongly influence their optical properties, and while compounds 2 and 3 emit near the limit of the visible range, complex 1 emits in the infrared region. DFT calculations have also been carried out in order to determine the origin of the electronic transitions responsible for their optical properties.

Assembly of Luminescent Chiral Gold(I)-Sulfido Clusters via Chiral Self-Sorting

Due to the ubiquity of chirality in nature, chiral self-assembly involving self-sorting behaviors has remained as one of the most important research topics of interests. Herein, starting from a racemic mixture of SEG-based (SEG=SEGPHOS) chlorogold(I) precursors, a unique chiral butterfly-shape hexadecanuclear gold(I) cluster (Au16 ) with different ratios of RSEG and SSEG ligands is obtained via homoleptic and heterochiral self-sorting. More interestingly, by employing different chlorogold(I) precursors of opposite chirality (such as RSEG -Au2 and SBIN -Au2 (BIN=BINAP)), an unprecedented heteroleptic and heterochiral self-sorting strategy has been developed to give a series of heteroleptic chiral decanuclear gold(I) clusters (Au10 ) with propellor-shape structures. Heterochiral and heteroleptic self-sorting have also been observed between enantiomers of homoleptic chiral Au10 clusters to result in the heteroleptic chiral Au10 clusters via cluster-to-cluster transformation. Incorporation of heteroleptic ligands is found to decrease the symmetry from S4 of homoleptic meso Au10 to C2 of heteroleptic chiral Au10 clusters. The chirality has been transferred from the axial chiral ligands and stored in the heteroleptic gold(I) clusters.

From Mono- to Polynuclear 2-(Diphenylphosphino)pyridine-Based Cu(I) and Ag(I) Complexes: Synthesis, Structural Characterization, and DFT Calculations

A series of monometallic Ag(I) and Cu(I) halide complexes bearing 2-(diphenylphosphino)pyridine (PyrPhos, L) as a ligand were synthesized and spectroscopically characterized. The structure of most of the derivatives was unambiguously established by X-ray diffraction analysis, revealing the formation of mono-, di-, and tetranuclear complexes having general formulas MXL3 (M = Cu, X = Cl, Br; M = Ag, X = Cl, Br, I), Ag2X2L3 (X = Cl, Br), and Ag4X4L4 (X = Cl, Br, I). The Ag(I) species were compared to the corresponding Cu(I) analogues from a structural point of view. The formation of Cu(I)/Ag(I) heterobimetallic complexes MM'X2L3 (M/M' = Cu, Ag; X = Cl, Br, I) was also investigated. The X-ray structure of the bromo-derivatives revealed the formation of two possible MM'Br2L3 complexes with Cu/Ag ratios, respectively, of 7:1 and 1:7. The ratio between Cu and Ag was studied by scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDX) measurements. The structure of the binuclear homo- and heterometallic derivatives was investigated using density functional theory (DFT) calculations, revealing the tendency of the PyrPhos ligands not to maintain the bridging motif in the presence of Ag(I) as the metal center.

Template-assisted synthesis of isomeric copper(i) clusters with tunable structures showing photophysical and electrochemical properties

A comparative study of structure-property relationships in isomeric and isostructural atomically precise clusters is an ideal approach to unravel their fundamental properties. Herein, seven high-nuclearity copper(i) alkynyl clusters utilizing template-assisted strategies were synthesized. Spherical Cu36 and Cu56 clusters are formed with a [M@(V/PO4)6] (M: Cu2+, Na+, K+) skeleton motif, while peanut-shaped Cu56 clusters feature four separate PO4 templates. Experiments and theoretical calculations suggested that the photophysical properties of these clusters are dependent on both the inner templates and outer phosphonate ligands. Phenyl and 1-naphthyl phosphate-protected clusters exhibited enhanced emission features attributed to numerous well-arranged intermolecular C-H⋯π interactions between the ligands. Moreover, the electrocatalytic CO2 reduction properties suggested that internal PO4 templates and external naphthyl groups could promote an increase in C2 products (C2H4 and C2H5OH). Our research provides new insight into the design and synthesis of multifunctional copper(i) clusters, and highlights the significance of atomic-level comparative studies of structure-property relationships.

Thiacalix[4]arene-protected alkynyl Agn (n = 9, 18) nanoclusters: syntheses, structural characterizations, photocurrent responses and fluorescence properties

Two thiacalix[4]arene-protected silver(I) alkynyl nanoclusters, [Na2(H2O)2][Ag9(TC4A)(tBuCC)4(CH3OH)2(SbF6)0.5(OH)2.5]·3.5H2O·CH3OH (1, abbreviated as Ag9) and [Ag9(TC4A)(tBuCC)4(CF3COO)]2·4CH3OH (2, abbreviated as Ag18), were synthesized by the reaction of [tBuCCAg]n, p-tert-butylthiacalix[4]arene (H4TC4A), NaBH4, and AgSbF6 or CF3COOAg in the mixed solvent of methanol-trichloromethane-toluene under solvothermal conditions, respectively. Driven by SbF6- and CF3COO- with different coordination properties, the structural unit [Ag9(TC4A)(tBuCC)4]+ in both the compounds migrated in different modes, accompanied by distinct Ag⋯Ag distances. Ag9 and Ag18 exhibit similar UV-Vis absorption and diffuse reflection spectra along with contrary tendency between photocurrent responses and solid-state fluorescence. The solution stability of Ag9 and Ag18 was demonstrated by 1H NMR and MALDI-TOF mass spectrometry. The fluorescence responses of Ag9 and Ag18 towards different organic molecules were also investigated, which indicated that the polarity of solvent has a certain effect on the emission intensities of Ag9 and Ag18. This study provides a positive guide for the controlled synthesis and further study of the structure-activity relationship of thiacalix[4]arene-protected silver alkynyl nanoclusters.

Two New Red/Near-Infrared Ir(Ⅲ) Complexes with Reversible and Force-Induced Enhanced Mechanoluminescence

Two novel ionic red/near-infrared Ir(III) complexes (Ir1 and Ir2) were reasonably designed and prepared using 2-(1-isoquinolinyl)-9,10-anthraquinone as the main ligand and 4,4'-dimethyl-2,2'-bipyridyl and 4,4'-dimethoxy-2,2'-bipyridyl as the auxiliary ligands, respectively. Both complexes showed bright phosphorescence in solution (peak at 618 nm with a shoulder at 670 nm). Interestingly, the phosphorescence peak of two Ir(III) complexes showed a blue-shift of about 36 nm after being ground. Simultaneously, both complexes exhibited mechanical force-induced enhanced emission, and the intensity of the luminescence for Ir1 and Ir2 increased by around two times compared to the one before being ground, respectively. Powder X-ray diffraction (PXRD) and time-dependent density functional theory (TD-DFT) calculation were utilized to understand well the mechanism of this phenomenon and suggested that the destruction of the well-ordered crystalline nature and the decline in triplet-triplet annihilation maybe responsible for the pressure-induced blue-shift and the enhancement of the phosphorescence.

Solvent-Mediated Separation and Reversible Transformation of 1D Supramolecular Polymorphs Built from [W10O32]4- Templated 48-Nuclei Silver(I) Cluster

Although the C-H···O interaction is an essential component in determining the molecular packing in solids and the properties in supramolecular chemistry, it presents a significant challenge when trying to use it in the crystal engineering of complex metallosupramolecules, even though it is a relatively weak supramolecular force. The first pair of high-nuclearity silver-cluster-based one-dimensional (1D) polymorphs built from supramolecular synthon [W₁₀O₃₂@Ag₄₈(CyS)₂₄(NO₃)₁₆]·4NO₃ (Cy = cyclohexyl) bridged by four grouped inorganic NO₃^- ligands is initially synthesized as a mixed phase and further individually crystallized as a pure phase by virtue of tuning intermolecular C-H···O interaction through altering the composition ratio of ternary solvent system. Increasing highly polar and hydrogen-bonding methanol strengthens the solvation effect reflected by the change of coordination orientation of surface NO₃^- ligands, which dominates the packing of the 1D chains in the crystal lattice, resulting in the crystallization of polymorphs from tetragonal to monoclinic. The two crystalline forms can also be reversibly transformed to each other in an appropriate solvent system. Correspondingly, the two polymorphs display distinct temperature-dependent photoluminescence behaviors, which are ascribed to the variation of noncovalent interchain C-H···O interactions along with the temperature. More importantly, benefiting from the suppression of fluorescence, both polymorphs offer excellent photothermal conversion properties which were further applied to remote-controlled laser ignition. These findings may open more avenues for the application of solvent-mediated intermolecular interaction in controlling the molecule arrangement as well as the optical properties.

Homoleptic Alkynylphosphonium Au(I) Complexes as Push-Pull Phosphorescent Emitters

A series of compounds P1-P4 bearing terminal alkynyl sites connected with a phosphonium group via different π-conjugated linkers have been synthesized. The compounds themselves are efficient push-pull emitters and exhibit bright fluorescence in blue and near-UV regions. P1-P4 were used as alkynyl ligands to obtain a series of homoleptic bis-alkynyl Au(I) complexes 1-4. The complexes demonstrate bright phosphorescence and dual emission with dominating phosphorescence (2-4). Terphenyl derivative complex 3 exhibits warm white emission in DMSO solution and pure white emission in PMMA films. Time-dependent density functional theory calculations have shown that the T₁ excited state has a hybrid MLCT/ILCT nature with a dominant contribution of charge transfer across a ligand-centered "D-π-A" system. The variation of linker allows tuning the effect of intermolecular charge transfer and thus changing the electronic and photophysical properties of the organogold "D-π-A" system. The results presented unambiguously display the advances of the conception of organometallic "D-π-A" construction.

Stimuli-Induced Reversible Transformation between Decanuclear and Pentanuclear Gold(I) Sulfido Complexes

Decanuclear and pentanuclear gold(I) sulfido complexes of phenanthrene- and dibenzothiophene-based diphosphine ligands were synthesized and characterized. Unprecedented stimuli-induced reversible transformation between decanuclear and pentanuclear gold(I) sulfido complexes was observed, which could be readily monitored by NMR and UV-vis absorption spectroscopy in solution. Remarkably, the decanuclear gold(I) sulfido complex (Au₁₀-L^Ph) was found to show a highly reversible transformation process, which is stable for over 10 successive cycles in solution. The stimuli-induced reversible transformation behavior of the gold(I) sulfido complexes was found to depend on the P-P bite distance of the bidentate phosphine ligands.

Heterometallic Coinage Metal Acetylenediide Clusters Showing Tailored Thermochromic Luminescence

Acetelyenediide (C₂ ^2- ) species have been encapsulated in bimetallic and trimetallic clusters: [(AuL)₆ Ag₇ (C≡C)₃ ](BF₄ )₇ (2) and [(AuL)₆ AgCu₆ (C≡C)₃ ](BF₄ )₇ (3), L=phenylbis(2-pyridyl)phosphine (PPhpy₂ ). Single-crystal X-ray diffraction analysis revealed that they are isostructural and six silver atoms in 2 are replaced with copper in 3. Both clusters have a trefoil skeleton, which can be viewed as three trigonal bipyramidal (LAu-C≡C-AuL)M₂ Ag (M=Ag/Cu) motifs sharing a common silver atom. TDDFT calculations showed Cu-doping significantly increases the energy level of (C₂ -Cu)-involved occupied orbital, thus inducing interesting transition coupling of dual-emission at low temperature. This work not only provides a strategy for constructing heterometallic clusters, but also shows the prospect for pursuing novel thermochromic luminescent materials by incorporating multi-congeneric metal components.

Dual Emissive Gold(I)-Sulfido Cluster Framework Capable of Benzene-Cyclohexane Separation in the Solid State Accompanied by Luminescence Color Changes

A decanuclear gold(I)-sulfido complex, [(L^H)₄Au₁₀S₄]Cl₂ (L^H-Au₁₀S₄-Cl, where L^H = 4,5-bis(diphenylphosphanyl)-2H-1,2,3-triazole), assembled from the reaction of H₂S with the chlorogold(I) precursor obtained from the click reaction of [dppa(AuCl)₂] (where dppa = 1,2-bis(diphenylphosphino)acetylene) with NaN₃, is shown to display a bright dual green and red emission in the solid state. Single crystal X-ray diffraction (SCXRD) studies indicate a gold(I) cluster-based framework assembled through intermolecular halogen···hydrogen bonds as well as other weak interactions. The framework of L^H-Au₁₀S₄-Cl is found to display high stability toward solvent molecules, with capability to encapsulate solvent molecules, such as benzene and cyclohexane, inside the crystal lattice voids via a single-crystal-to-single-crystal (SCSC) transformation. With different degrees of influence on the dual green and red emission, crystalline solids of L^H-Au₁₀S₄-Cl exhibit remarkable solvatochromic luminescence in the presence of benzene and cyclohexane. Notably, due to the size confinement of the lattice cavities, the L^H-Au₁₀S₄-Cl solids exhibit a high selectivity (>95%) toward benzene in a mixture of equimolar concentration of benzene and cyclohexane. This work has demonstrated the promising capability of gold(I)-sulfido cluster frameworks to serve as luminescent functional materials for the separation of benzene and cyclohexane.

Trinuclear cationic silver nanoclusters based-on bis-(phosphine) ligands and stabilized by CF3SO3− anions

Three trinuclear cationic silver nanoclusters based-on bis-(phosphine) ligands and stabilized by CF₃SO₃⁻ anions, displayed excellent photocurrent responses and electrochemical properties.

Keep it tight: a crucial role of bridging phosphine ligands in the design and optical properties of multinuclear coinage metal complexes

Copper subgroup metal ions in the +1 oxidation state are classical candidates for aggregation via non-covalent metal-metal interactions, which are supported by a number of bridging ligands. The bridging phosphines, soft donors with a relatively labile coordination to coinage metals, serve as convenient and essential components of the ligand environment that allow for efficient self-assembly of discrete polynuclear aggregates. Simultaneously, accessible and rich modification of the organic spacer of such P-donors has been used to generate many fascinating structures with attractive photoluminescent behavior. In this work we consider the development of di- and polynuclear complexes of M(i) (M = Cu, Ag, Au) and their photophysical properties, focusing on the effect of phosphine bridging ligands, their flexibility and denticity.

Ultrabright Au@Cu14 nanoclusters: 71.3% phosphorescence quantum yield in non-degassed solution at room temperature

The photoluminescence of metal nanoclusters is typically low, and phosphorescence emission is rare due to ultrafast free-electron dynamics and quenching by phonons. Here, we report an electronic engineering approach to achieving very high phosphorescence (quantum yield 71.3%) from a [Au@Cu₁₄(SPh ^t Bu)₁₂(PPh(C₂H₄CN)₂)₆]⁺ nanocluster (abbreviated Au@Cu ₁₄ ) in non-degassed solution at room temperature. The structure of Au@Cu ₁₄ has a single-Au-atom kernel, which is encapsulated by a rigid Cu(I) complex cage. This core-shell structure leads to highly efficient singlet-to-triplet intersystem crossing and suppression of nonradiative energy loss. Unlike the phosphorescent organic materials and organometallic complexes-which require de-aerated conditions due to severe quenching by air (i.e., O₂)-the phosphorescence from Au@Cu ₁₄ is much less sensitive to air, which is important for lighting and biomedical applications.

Total Structure Determination of the Largest Alkynyl-Protected fcc Gold Nanocluster Au110 and the Study on Its Ultrafast Excited-State Dynamics

Great attention has been paid to nanoclusters having face-centered-cubic (fcc) metal kernels, because of the similarity of metal packing to that of bulk gold. So far, there is no precedent example of an all-alkynyl-protected fcc gold nanocluster with more than 100 gold atoms. We report the synthesis and total structure determination of an alkynyl-protected gold nanocluster [NEt₃H]₂[Au₁₁₀(p-CF₃C₆H₄C≡C)₄₈] (Au₁₁₀). It has an fcc Au₈₆ kernel with 24 peripheral Au(C≡CR)₂ staples. The Au₈₆ kernel consists of six close packing layers in the pattern of Au₆:Au₁₆:Au₂₁:Au₂₁:Au₁₆:Au₆. Electronic absorption spectroscopy shows Au₁₁₀ has a molecular-like discrete electronic structure, and transient absorption experiments reveal its nonmetallic nature.

Core-dependent properties of copper nanoclusters: valence-pure nanoclusters as NIR TADF emitters and mixed-valence ones as semiconductors

While valence-pure copper alkynyl nanoclusters show near-infrared TADF, the mixed-valence ones exhibit semiconductivity.

We report herein that copper alkynyl nanoclusters show metal-core dependent properties via a charge-transfer mechanism, which enables new understanding of their structure–property relationship. Initially, nanoclusters 1 and 2 bearing respective Cu(i)₁₅ (C1) and Cu(i)₂₈ (C2) cores were prepared and revealed to display near-infrared (NIR) photoluminescence mainly from the mixed alkynyl → Cu(i) ligand-to-metal charge transfer (LMCT) and cluster-centered transition, and they further exhibit thermally activated delayed fluorescence (TADF). Subsequently, a vanadate-induced oxidative approach to in situ generate a nucleating Cu(ii) cation led to assembly of 3 and 4 featuring respective [Cu(ii)O₆]@Cu(i)₄₇ (C3) and {[Cu(ii)O₄]·[VO₄]₂}@Cu(i)₄₆ (C4) cores. While interstitial occupancy of Cu(ii) triggers inter-valence charge-transfer (IVCT) from Cu(i) to Cu(ii) to quench the photoluminescence of 3 and 4, such a process facilitates charge mobility to render them semiconductive. Overall, metal-core modification results in an interplay between charge-transfer processes to switch TADF to semiconductivity, which underpins an unusual structure–property correlation for designed synthesis of metal nanoclusters with unique properties and functions.

Atomically Precise Gold-Levonorgestrel Nanocluster as a Radiosensitizer for Enhanced Cancer Therapy

Gold nanoclusters have become promising radiosensitizers due to their ultrasmall size and robust ability to adsorb, scatter, and re-emit radiation. However, most of the previously reported gold nanocluster radiosensitizers do not have a precise atomic structure, causing difficulties in understanding the structure-activity relationship. In this study, a structurally defined gold-levonorgestrel nanocluster consisting of Au₈(C₂₁H₂₇O₂)₈ (Au₈NC) with bright luminescence (58.7% quantum yield) and satisfactory biocompatibility was demonstrated as a nanoradiosensitizer. When the Au₈NCs were irradiated with X-rays, they produced reactive oxygen species (ROS), resulting in irreversible cell apoptosis. As indicated by in vivo tumor formation experiments, tumorigenicity was significantly suppressed after one radiotherapy treatment with the Au₈NCs. In addition, compared with tumors treated with X-rays (4 Gy) alone, tumors treated with the nanosensitizer exhibited an inhibition rate of 74.2%. This study contributes to the development of atomically precise gold nanoclusters as efficient radiosensitizers.

Linear Copper Complex Arrays as Versatile Molecular Strings: Syntheses, Structures, Luminescence, and Magnetism

The defined linear arrangement of metal atoms in discrete coordination complexes or polymers is still one of the most intriguing challenges in synthetic chemistry. These chain arrangements are of fundamental importance, because of their potential applications as molecular wires and single molecule magnets (SMM) in microelectronic devices on a molecular scale. Oligonuclear Group 11 metal complexes with suitable bridging ligands, specifically those that are based on copper as the first choice of a cheap precursor coinage metal, are of particular interest in this regard. This is due to the superior luminescence properties of these linear clusters that often show d¹⁰ ⋅⋅⋅d¹⁰ interactions in their molecular structures. The combination of Cu^I with heavier coinage metal ions results in tunable emissive arrays that are also stimuli-responsive. Thus, both linear multinuclear Cu^I and linear heteropolymetallic Cu^I /Ag^I as well as Cu^I /Au^I clusters are excellent candidates for applications in molecular/organic light-emitting devices (OLEDs). Alternatively, paramagnetic multinuclear cupric arrays are prominent as potential molecular wires with enhanced magnetic properties through multiple coupled d⁹ centers. This Review covers the whole range of linear multinuclear assemblies of cuprous and cupric ions in complexes and coordination polymers, their syntheses, photophysical behavior, and magnetic properties. Moreover, recent advances in the rapidly progressing field of hetero-Cu^I /Ag^I and Cu^I /Au^I molecular strings are also discussed.

Estradiol dimer inhibits tubulin polymerization and microtubule dynamics

Microtubule dynamics is one of the major targets for new chemotherapeutic agents. This communication presents the synthesis and biological profiling of steroidal dimers based on estradiol, testosterone and pregnenolone bridged by 2,6-bis(azidomethyl)pyridine between D rings. The biological profiling revealed unique properties of the estradiol dimer including cytotoxic activities on a panel of 11 human cell lines, ability to arrest in the G2/M phase of the cell cycle accompanied with the attenuation of DNA/RNA synthesis. Thorough investigation precluded a genomic mechanism of action and revealed that the estradiol dimer acts at the cytoskeletal level by inhibiting tubulin polymerization. Further studies showed that estradiol dimer, but none of the other structurally related dimeric steroids, inhibited assembly of purified tubulin (IC₅₀, 3.6 μM). The estradiol dimer was more potent than 2-methoxyestradiol, an endogenous metabolite of 17β-estradiol and well-studied microtubule polymerization inhibitor with antitumor effects that was evaluated in clinical trials. Further, it was equipotent to nocodazole (IC₅₀, 1.5 μM), an antimitotic small molecule of natural origin. Both estradiol dimer and nocodazole completely and reversibly depolymerized microtubules in interphase U2OS cells at 2.5 μM concentration. At lower concentrations (50 nM), estradiol dimer decreased the microtubule dynamics and growth life-time and produced comparable effect to nocodazole on the microtubule dynamicity. In silico modeling predicted that estradiol dimer binds to the colchicine-binding site in the tubulin dimer. Finally, dimerization of the steroids abolished their ability to induce transactivation by estrogen receptor α and androgen receptors. Although other steroids were reported to interact with microtubules, the estradiol dimer represents a new structural type of steroid inhibitor of tubulin polymerization and microtubule dynamics, bearing antimitotic and cytotoxic activity in cancer cell lines.

Copper inter-nanoclusters distance-modulated chromism of self-assembly induced emission

Metal nanoclusters (NCs) have attracted broad attention for their molecular-like electronic structures and unique emission properties, but the difficulty in controlling emission color greatly limits their application in illumination and display. In this work, we demonstrate the capability to control the self-assembly induced emission (SAIE) of Cu NCs by modulating the inter-NC distance in the self-assembly materials, which is capable of tuning the emission color from green to red. The inter-NC distance is mainly modulated by controlling the experimental variables during the NC self-assembly, such as the species of the solvents and ligands, duration of assembly, temperature, and so forth. These experimental variables influence the balance of inter-NC weak interactions, thus altering the distance of as-assembled NCs. The variation of the inter-NC distance greatly influences the photo-physical behavior of Cu NCs, and in particular the ligand-to-Cu-Cu charge transfer, permitting the tuning of the emission color. As the Cu NCs self-assembly materials exhibit strong, stable, and color-tunable SAIE, they are employed as the color conversion materials for fabricating white light-emitting diodes.

Assembly of strongly phosphorescent hetero-bimetallic and -trimetallic [2]catenane structures based on a coinage metal alkynyl system

Homo-metallic metal alkynyl complexes exhibit interesting catenane structures, but their hetero-metallic catenane counterparts are under-developed. In this work, we report rare examples of bimetallic Au-Cu (DtbpC 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C^- ligand; Dtbp = 3,5-di-tert-butylphenyl), Au-Ag ( ^t BuC 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C^- ligand), and Au-Cu, Au-Ag (C6-FluoC 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C^- ligand; C6-Fluo = 9,9-dihexyl-9H-fluoren-2-yl) complexes as well as a trimetallic Au-Ag-Cu (C6-FluoC 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C^- ligand) complex, which feature [2]catenane structures. The formation of the [2]catenane structure is significantly affected by the coinage metal ion(s) and change of the structure of the alkynyl ligand. These hetero-metallic [2]catenane structures are strongly luminescent with tunable emission λ_max from 503 to 595 nm and Φ values up to 0.83.

Engineering the Self-Assembly Induced Emission of Cu Nanoclusters by Au(I) Doping

Aggregation-induced emission (AIE) and self-assembly induced emission (SAIE) effects have been employed to tune the emission properties of metal nanoclusters (NCs). However, it is still not possible to further enhance the photoluminescence quantum yields (PLQYs) and control the emission colors of the NCs using AIE and SAIE. On the basis of our recent work studying the contribution of Cu(I) defects in the SAIE of Cu NCs, in this article, Au(I) was doped into Cu NC self-assembled nanosheets (NSASs) to construct a more stable Au(I)-centered state. As a result, the PLQYs, emission stability, and tunability of emission colors of the Cu NSASs were significantly improved. Detailed studies reveal that the doped Au(I) induces a Au(I)-Cu(I) metallophilic interaction, which leads to a ligand-to-Cu-Au charge transfer, which facilitates the relaxation of excited electrons via a radiative pathway, thereby enhancing the emission intensity. The charge transfer from Cu to Au lowers the energy, thus leading to the red-shift of PL emission. Au(I) is likely doped into the Cu NSASs rather than in individual NCs, because 0.3% Au doping is enough to alter the emission properties. By mixing Au(I)-doped Cu NSASs with different emission colors (due to different Au doping percentages) as color conversion materials on commercially available 365 nm GaN chips, a white light-emitting diode prototype is fabricated.

Anion-templated nanosized silver clusters protected by mixed thiolate and diphosphine

S^2-, MoO₄^2-, and Mo₆O₂₂^8- were successfully employed as templates in the formation of six high-symmetry polynuclear silver clusters as exemplified in the single-crystal X-ray structures of [S@Ag₁₈(^tBuC₆H₄S)₁₆(dppp)₄]·DMF·5CH₃CN·3CH₃OH (1), [MoO₄@Ag₂₄(MeC₆H₄S)₁₂(dppm)₆(MoO₄)₄]·2BF₄·C₂H₅NO (2), [MoO₄@Ag₂₄(MeC₆H₄S)₁₂(dppm)₆(MoO₄)₄]·2CF₃SO₃ (3), [MoO₄@Ag₂₄(MeC₆H₄S)₁₂(dppf)₆(MoO₄)₄]·2CF₃SO₃ (4), [MoO₄@Ag₂₄(MeC₆H₄S)₁₂(dppb)₆(MoO₄)₄]·2CF₃SO₃ (5) and [Mo₆O₂₂@Ag₄₆(^tBuC₆H₄S)₃₂(dppm)₄(CH₃CN)₈]·6CF₃SO₃ (6) (dppp = 1,3-bis(diphenylphosphino)propane, dppm = bis(diphenylphosphino)methane, dppf = 1,1'-bis(diphenylphosphino)ferrocene and dppb = 1,4-bis(diphenylphosphino)butane). Cluster 1 is a S^2--centered octadecanuclear banana-shaped molecule. Clusters 2-5 have similar structures consisting of a tetrahedron of a MoO₄^2- core and four MoO₄^2- where three silver atoms cap each face and a pair sits on each edge, giving tetraicosanuclear ball-shaped molecules. Although different diphosphine ligands and silver salts were used in the syntheses, 2-5 contain a common building cluster unit with similar geometry and nuclearity. With (Bu₄N)₂Mo₆O₁₉ as a template, a giant 46-silver-atom cluster encapsulates an in situ modified Mo₆O₂₂^8- unit. The nuclearity and geometry depend on the size and shape of the templates. High-resolution electrospray mass spectrometry (HR-ESI-MS) analyses of 4 indicate its exceptionally high stability in acetonitrile. The solid-state luminescence of 1 as a function of the temperature exhibits thermochromism from red to yellow due to the different intensities of the two bands. This work established a new strategy for the construction of polynuclear silver clusters using an anionic template and mixed S- and P-donor ligands where a promising approach for building novel dual emissive materials is unraveled.

New Au(i)–Cu(i) heterometallic complexes: the role of bridging pyridazine ligands in the presence of unsupported metallophilic interactions

The use of N-donor pyridazine ligands in different amounts in the reaction with a Au(i)/Cu(i) precursor allows the control of metallophilic interactions in the solid state.