Sulfido Clusters Research Articles

Graphene Decorated With Mo3S7 Clusters for Sensing CO2

AbstractThis paper reports for the first time a gas‐sensitive nanohybrid based on trinuclear molybdenum sulfido clusters ((Bu4N)2[Mo3(μ3‐S)(μ‐S2)3Cl6] (Mo3S7)) supported on graphene flakes (Mo3S7@Graphene). The nanomaterial, once implemented in a chemoresistive device, changes its electrical resistivity when exposed, at room temperature (RT), to toxic and harmful gases, such as hydrogen (H2), carbon dioxide (CO2), carbon monoxide (CO), and benzene. Particularly, the Mo3S7@Graphene hybrid shows an outstanding sensing performance toward CO2. Theoretical calculations provide a better understanding of the plausible gas sensing mechanisms. These findings open the door for a new generation of molybdenum sulfido cluster‐based sensors in which electronic interrogation can be implemented, advancing toward the realization of highly sensitive gas sensing.

Evolution of Polynuclear Gold(I) Sulfido Complexes from Clusters and Cages to Macrocycles.

Two unprecedented tetratriacontanuclear and tetraicosanuclear gold(I) sulfido clusters (denoted as Au34-LMe and Au24-LCbz) with different temperature-induced stimulus-responsive behavior and emission property have been constructed by taking advantage of the judiciously designed bidentate phosphine ligand. Au34-LMe represents the highest nuclearity of the gold(I) sulfido cluster with more than a thousand atoms in the molecule. Octagonal macrocycles based on metal-cluster nodes have been assembled for the first time. The self-assembly and temperature-induced stimulus-responsive processes were monitored by 1H and 31P{1H} NMR spectroscopy, and the identities of the discrete gold(I) complexes were established by single-crystal structural analysis and high-resolution electrospray ionization mass spectrometry data. The steric effects exerted by the substituents on the V-shaped 1,3-bis(diphenylphosphino)benzene ligand have been shown to govern the self-assembly from the 1D cluster and 3D cage to 2D macrocycles. This work not only offers a new strategy to construct and regulate the structure of 2D macrocyclic gold(I) sulfido complexes but also lays the foundation for the future precise design and controlled construction of higher polygonal and cluster-node macrocycles.

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.

Photo- and Temperature-Induced Reversible Structural Transformation between Dodecanuclear and Pentadecanuclear Gold(I) Sulfido Complexes.

Stimuli-responsive structural transformation has attracted much attention for its potential to mimic the behavior of biological transformations and functions. Here, two unprecedented dodecanuclear and pentadecanuclear gold(I) sulfido clusters (denoted trans-Au12 and trans-Au15, respectively) with impressive stimuli-responsive interconversion have been obtained by taking advantage of the judiciously designed tridentate phosphine ligand Ltrans as the building block. Both UV light and temperature can be applied to trigger the structural conversions between trans-Au12 and trans-Au15. In addition, NMR, high-resolution electrospray ionization mass spectrometry, and UV-vis absorption spectroscopy have been employed to monitor the transformation process and decipher the mechanism of structural conversion. This work not only provides a paradigm to investigate photo-induced cluster-to-cluster transformation based on polydentate phosphine ligands but also offers a new direction for the construction of the stimuli-responsive materials.

Control of the pore chemistry in metal-organic frameworks for efficient adsorption of benzene and separation of benzene/cyclohexane

Control of the pore chemistry in metal-organic frameworks for efficient adsorption of benzene and separation of benzene/cyclohexane

Synthesis, Electrochemistry, Photophysics, and Photochemistry of a Discrete Tetranuclear Copper(I) Sulfido Cluster.

A tetranuclear copper(I) complex, [Cu4{μ-(Ph2P)2NH}4(μ4-S)](PF6)2 (1), was synthesized. It was found to display intense and long-lived phosphorescence in the solid and solution states. The lowest-energy excited state was assigned as ligand-to-metal charge transfer (LMCT) [S2- → Cu4] mixed with some metal-centered (ds/dp) character. In addition, the phosphorescent state of this complex was found to be quenched by pyridinium acceptors via an oxidative electron-transfer quenching process. An excited-state reduction potential of -1.74 V versus saturated salt calomel electrode was estimated through oxidative quenching studies with a series of structurally related pyridinium acceptors, indicative of its strong reducing power in the excited state. From the transient absorption difference spectrum of the tetranuclear copper(I) sulfido complex and 4-(methoxycarbonyl)-N-methylpyridinium hexafluorophosphate, in addition to the characteristic absorption of the pyridinyl radical at ca. 395 nm, two absorption bands at ca. 500 and 660 nm were also observed. The former was assigned as an LMCT absorption [S2- → Cu4] and the latter as an intervalence charge-transfer transition, associated with the mixed-valence species CuI/CuI/CuI/CuII.

Synthesis, structural characterization, and photophysical studies of decanuclear gold(I) sulfido complexes with carbazole‐derived ligands

AbstractDecanuclear gold(I) sulfido clusters, [Au10{μ‐Ph2PN(C6H4−Cbz)PPh2}4(μ3‐S)4](PF6)2 (1) and [Au10{μ‐Ph2PN(C6H4−tBu2Cbz)PPh2}4(μ3‐S)4](PF6)2 (2), with bridging bis(diphenylphosphino)amine ligands were synthesized and characterized. The propeller‐like molecular structure of 1 was determined via X‐ray crystal structure analysis. Both complexes were found to show intense dual green and orange phosphorescence upon photoexcitation at ambient temperature. The emissions were tentatively assigned to originate from the excited states derived from the phosphine‐centered intraligand (IL) transition and ligand‐to‐metal‐metal charge transfer (LMMCT) (S→Au) transition.

Substituent-Mediated Transformation of Polynuclear Gold(I)-Sulfido Complexes—From Pentanuclear to Octadecanuclear Cluster-to-Cluster Transformation

Substituent-Mediated Transformation of Polynuclear Gold(I)-Sulfido Complexes—From Pentanuclear to Octadecanuclear Cluster-to-Cluster Transformation

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, [(LH)4Au10S4]Cl2 (LH-Au10S4-Cl, where LH = 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 LH-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 LH-Au10S4-Cl exhibit remarkable solvatochromic luminescence in the presence of benzene and cyclohexane. Notably, due to the size confinement of the lattice cavities, the LH-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.

Preparation and luminescence properties of a M16 heterometallic coinage metal chalcogenide cluster.

A hexadeca-nuclear, N-heterocyclic carbene stabilized gold(i)-copper(i)-sulfido cluster is reported, which emits yellow-orange in the solid state. The nature of this emission is examined, supported by combined theoretical and spectroscopic studies.

Decanuclear Gold(I) Sulfido Pseudopolymorphs Displaying Stimuli-Responsive RGBY Luminescence Changes

Decanuclear gold(I) sulfido clusters, [Au10{μ-Ph2PN(R)PPh2}4(μ3-S)4](PF6)2], with propeller-shaped structures were obtained using bridging bis(diphenylphosphino)amine with alkylpyridine pendant gro...

A Gold Quartet Framework with Reversible Anisotropic Structural Transformation Accompanied by Luminescence Response

Summary Hierarchy and chirality are the fundamental characteristics of biomolecules. Chemistry on hierarchical self-assembly and spontaneous symmetry breaking helps to uncover the mechanism of living activities and the origin of chirality in nature. Herein, we describe a chiral gold quartet framework (GQF) with C4-symmetric structure hierarchically aggregated from an achiral anionic [Au10(dpptrz)4S4]2− (dpptrz-Au10), which was acquired via click-reaction-induced and Au(I)⋅⋅⋅Au(I)-interaction-directed cluster-to-cluster transformation (CCT) from the rationally designed [(dppa)6Au18S8]2+ (dppa-Au18). Inter-cluster hydrogen bonding and alkali ion coordination were observed to assist the hierarchical self-assembly and chiral self-organization of the GQF. Upon exposing the crystal to vacuum, the bottom-up constructed GQF showed an anisotropic structural transformation accompanied by a visual luminescence change in a single-crystal-to-single-crystal (SCSC) manner that became reversible upon removal of vacuum. This research largely advances the potential of polynuclear gold(I)-sulfido clusters in hierarchical self-assembly and luminescent materials.

Tetradecanuclear and Octadecanuclear Gold(I) Sulfido Clusters: Synthesis, Structures, and Luminescent Selective Tracking of Lysosomes in Living Cells.

Reactions of the phosphanyl-gold(I) precursor [(AuCl)2(bdppmapy)] (1; bdppmapy = N,N-bis(diphenylphosphanylmethyl)-2-aminopyridine) with Na2S in a 1:1 or 1:2 molar ratio gave rise to one tetradecanuclear and one octanuclear Au(I) sulfido cluster, [Au14S6(bdppmapy)5]Cl2 (2) and [Au18S8(bdppmapy)6]Cl2 (3), respectively. The former displays a new structural framework in gold cluster chemistry. Compounds 2 and 3 showed strong green luminescence and were employed as excellent imaging probes to selectively light up the lysosomes of living cells. Their long-term tracking of lysosomes can be achieved for up to 36 h, while tracking with commercial Lyso-Tracker Red under the same conditions was limited to 3 h. Our work demonstrated the possibility of constructing novel gold(I) sulfido clusters supported by special P-N hybrid ligands and the potential application of these clusters as long-term selective trackers of lysosomes in bioimaging.

Trimetallic Cubane-Type Clusters: Transition-Metal Variation as a Probe of the Roots of Hypoelectronic Metallaheteroboranes.

In an effort to synthesize chalcogen-rich metallaheteroborane clusters of group 5 metals, thermolysis of [Cp*TaCl4] (Cp* = η5-C5Me5) with thioborate ligand Li[BH2S3] was carried out, affording trimetallic clusters [(Cp*Ta)3(μ-S)3(μ3-S)3B(R)], 1-3 (1, R = H; 2, R = SH; and 3, R = Cl). Clusters 1-3 are illustrative examples of cubane-type organotantalum sulfido clusters in which one of the vertices of the cubane is missing. In parallel to the formation of 1-3, the reaction also yielded tetrametallic sulfido cluster [(Cp*Ta)4(μ-S)6(μ3-S)(μ4-O)], 6, having an adamantane core structure. Compound 6 is one of the rarest examples containing the μ4-oxo unit with a heavier early transition metal, i.e., tantalum. In an effort to isolate selenium analogues of clusters 1-3, we have isolated the trimetallic cluster [(Cp*Ta)3(μ-Se)3(μ3-Se)3B(H)], 4, from the thermolytic reaction of [Cp*TaCl4] and Li[BH2Se3]. In contrast, the thermolysis of [Cp*TaCl4] with Li[BH2Te3] under the same reaction conditions yielded tantalum telluride complex [(Cp*Ta)2(μ-Te)2], 5. Compounds 1-4 are hypo-electronic clusters with an electron count of 50 cluster valence electrons. All these compounds have been characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy; infrared spectroscopy; mass spectrometry; and single-crystal X-ray crystallography. The density functional theory calculations were also carried out to provide insight into the bonding and electronic structures of these molecules.

Hydrogen evolution catalysis by molybdenum sulfides (MoSx): are thiomolybdate clusters like [Mo3S13]2− suitable active site models?

Recent results concerning molecular molybdenum sulfido clusters as model systems for heterogeneous hydrogen evolution catalysis by molybdenum sulfides are summarized and also compared to the related chemistry of the active site of the enzyme Mo-nitrogenase.

Thermodynamic-Driven Self-Assembly: Heterochiral Self-Sorting and Structural Reconfiguration in Gold(I)-Sulfido Cluster System.

By employing chiral precursors, a new class of chiral gold(I)-sulfido clusters with unique structures has been constructed. Interestingly, pure enantiomers of the precursors are found to self-assemble into chiral hexa- and decanuclear clusters sequentially, while a racemic mixture of them has resulted in heterochiral self-sorting of an achiral meso decanuclear cluster. Chirality has determined not only the symmetry and structures but also the photophysical behaviors of these clusters. The racemic mixture of decanuclear clusters undergoes rearrangement and heterochiral self-sorting to give a meso decanuclear cluster. The thermodynamic-driven heterochiral self-sorting of gold(I) clusters provides a means to develop controlled self-assembly that may be of relevance to the understanding of chirality in nature.

Synthesis, structure, and reactions of a copper-sulfido cluster comprised of the parent Cu2S unit: {(NHC)Cu}2(μ-S).

The synthesis of the first CuI2(μ-S) complex, {(IPr*)Cu}2(μ-S) (IPr* = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene; 1), has been accomplished via three synthetic routes: (1) salt metathesis between (IPr*)CuCl and Na2S; (2) silyl-deprotection reaction between (IPr*)Cu(SSiMe3) and (IPr*)CuF; and (3) acid-base reaction between (IPr*)Cu(SH) and (IPr*)Cu(O t Bu). The X-ray crystal structure of 1 exhibits two two-coordinate copper centers connected by a bent Cu-S-Cu linkage. Application of these synthetic routes to analogous precursors containing the sterically smaller ligand IPr (1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidene), in place of IPr*, resulted in the formation of a transient product proposed as {(IPr)Cu}2(μ-S) (2), which decomposes quickly in solution. The instability of 2 probably results from the insufficient steric protection provided by IPr ligands to the unsaturated Cu2(μ-S) core; in contrast, 1 is stable both in solution and solid state for weeks. The nucleophilic sulfido ligand in 1 reacts with haloalkyl electrophiles (benzyl halides and dibromoalkanes) with formation of C-S bonds, affording (IPr*)Cu(SCH2Ph) and cyclic thioethers, respectively.

Photoinduced isomerization-driven structural transformation between decanuclear and octadecanuclear gold(I) sulfido clusters.

Upon photoirradiation, isomerization of the ligands, 1,2-bis(diphenylphosphino)ethene (dppee) from the cis to the trans form in polynuclear gold(I) sulfido clusters, led to the structural transformation of the decagold(I) cluster to the octadecagold(I) cluster. Both polynuclear μ3-sulfido gold(I) clusters have been fully characterized by NMR, mass spectrometry, elemental analysis, and single crystal X-ray diffraction analysis. The transformation process could be readily detected and monitored by UV-vis absorption, emission, and (31)P NMR spectroscopy in solution. Supported and driven by Au(I)···Au(I) bonding interactions, the nuclearity and symmetry of these clusters were largely different from each other, resulting in completely distinct photophysical features.

Realgar as a building block for lanthanide clusters: encapsulation of a copper cluster by a lanthanide cluster.

The reactions of the divalent lanthanide metallocenes [Cp*2Ln(thf)2] (Cp* = η(5)-C5Me5; Ln = Sm, Yb) with realgar (As4S4) gave the open cage tetrametallic complex [(Cp*2Sm)(Cp*Sm)3AsS3(Cp*AsS2)2(thf)3] (1) or the trimetallic cage compound [(Cp*Yb)3As2S4(Cp*AsS2)(thf)2] (2), respectively, by reductive cleavage of the inorganic cage. As result of a Cp* transfer, the novel Cp*AsS2(2-) anion is formed. Moreover, the As2S4(4-) anion, which is bound in 2, is observed for the first time in coordination chemistry. Closed cage compounds are formed by either using bulkier ligands or a different As/S cage. The reaction of [Cp‴2Sm] (Cp‴ = (1,2,4-(t-Bu)3C5H2)) with As4S4 and the reaction of [Cp*2Yb(thf)2] with dimorphite (As4S3) gave the closed 11-vertex cage clusters [(Cp‴Sm)3(AsS3)2] (3) and [(Cp*Yb)3(AsS3)2] (4), respectively. The reaction of 3 with [CuMes] resulted in the formation of the Sm/S/Cu cluster [(Cp‴Sm(thf))4Cu4S6] (5), in which the Sm atoms encapsulate a classical Cu4S6(8-) cluster core. This is the first transition metal chalcogenide cluster encapsulated by f-elements. Alternatively, the endohedral cluster can thus be described as [Cu4@{(Cp‴Sm(thf))4S6}], in which a Cu4 tetrahedron is encapsulated by the samarium sulfido cluster {(Cp‴Sm(thf))4S6}.

Addition Reaction-Induced Cluster-to-Cluster Transformation: Controlled Self-Assembly of Luminescent Polynuclear Gold(I) μ3-Sulfido Clusters

Unprecedented addition reaction-induced gold(I) cluster-to-cluster transformation has been observed in the present work. Reaction of the chlorogold(I) precursor, [vdpp(AuCl)2] (vdpp = vinylidenebis(diphenylphosphine)) containing the diphosphine with unsaturated C═C bond, with H2S resulted in a series of polynuclear gold(I) μ3-sulfido clusters bearing Au(I)···Au(I) interactions; the identities of which have been fully characterized by NMR, electrospray-ionization mass spectrometry, elemental analysis, and single crystal X-ray diffraction analysis. Diverse research methods, including UV-vis absorption, (1)H NMR, and (31)P NMR spectroscopy, were employed to detect and monitor the transformation and assembly processes. Supported by single crystal structures, the existence of Au(I)···Au(I) bonding interactions sustains the diverse array of sophisticated polynuclear cluster structures and endues them with rich luminescence features.