Chalcogenide Clusters Research Articles

Controlling the White‐Light Generation of [(RSn)4E6]: Effects of Substituent and Chalcogenide Variation

AbstractAdamantane‐type organotin chalcogenide clusters of the general composition [(RT)4S6] (R=aromatic substituent, T=Si, Ge, Sn) have extreme non‐linear optical properties that lead to highly directional white‐light generation (WLG) upon irradiation with an IR laser diode. However, the mechanism is not yet understood. Now, a series of compounds [(RSn)4E6] (R=phenyl, cyclopentadienyl, cyclohexyl, benzyl, CH2CH2(C6H4)CO2Et; E=S, Se), were prepared, characterized, and investigated for their nonlinear optical properties. With the exception of crystalline [(BnSn)4S6], all these compounds exhibit WLG with similar emission spectra; slight blue‐shifts are observed by introduction of cyclopentadienyl substituents, while the introduction of Se in the inorganic core can provoke a red‐shift. These investigations disprove the initial assumption of an aromatic substituent being a necessary precondition; the precondition seems to be the presence of (cyclic) substituents providing enough electron density.

{(PhSn)3SnS6}{(MCp)3S4}] (M = W, Mo): Minimal Molecular Models of the Covalent Attachment of Metal Chalcogenide Clusters on Doped Transition Metal Dichalcogenide Layers.

With the aim to mimic the yet unknown covalent deposition of metal chalcogenide clusters on transition metal dichalcogenide (TMDC) MoS2 or WS2 layers, and thereby explore the interaction between the two systems and potential consequences on physical properties of the TMDC material, we synthesized heterobimetallic model systems. The heterocubane-type cluster [(SnCl3)(WCp)3S4] (1), the organotin-sulfidomolybdate cluster [{(PhSn)3SnS6}{(MoCp)3S4}] (2), and the corresponding tungstate [(PhSn)3SnS6{(WCp)3S4}] (3) were obtained in ligand exchange reactions from [(PhSn)4S6] and [M(CO)3CpCl]. Indeed, the {M3S4} cages in 1-3 resemble a section of the respective TMDC monolayers, altogether representing minimal molecular model systems for the adsorption of organotin sulfide clusters on MoS2 or WS2. The interaction between the {(MCp)3S4} and {(PhSn)3SnS6} subunits is characterized by multicenter bonding, rendering the respective Sn atom as Sn(II), hence driving the clusters into a mixed-valence Sn(IV)/Sn(II) situation, and the M atoms as M(IV) upon an in situ redox process. The attachment is thus weaker than via regular covalent M-S bonds, but definitely stronger than via van der Waals interactions that have been characteristic for all known interactions of clusters on TMDC surfaces so far. Computational analyses of an extended model mimicking the electronic situation in the cluster prove the analogy to a covalent attachment on TMDCs.

New 2D Assemblage of Supertetrahedral Chalcogenide Clusters with Tetravalent-Metal-Induced Interrupted Sites

Reported here are two new layered chalcogenide frameworks built from tetravalent-metal-induced triconnected supertetrahedral T3-InSnS clusters. This work demonstrates the significant role of tetravalent metal ion in building new 2D chalcogenide frameworks with the interrupted sites. Moreover, both chalcogenide materials show good performance on the photodegradation of methyl blue (MB).

On the Way Towards Fine Inorganic Synthesis: Manipulating Bridging Ligands in Chalcogenide Clusters

This review describes approaches to the targeted multistep synthesis of coordination compounds exemplified by Group 5 and 6 metal chalcogenide and oxide clusters and polynuclear compounds. Methods for the introduction of two different chalcogen atoms and methods for the synthesis of mixed oxide chalcogenide complexes are considered.

Tuning the Metal/Chalcogen Composition in Copper(I)-Chalcogenide Clusters with Cyclic (Alkyl)(amino)carbene Ligands.

A series of phosphorescent homo- and heterometallic copper(I)-chalcogenide clusters stabilized by cyclic (alkyl)(amino)carbene ligands [Cu4M4(μ3-E)4(CAACCy)4] (M = Cu, Ag, Au; E = S, Se) has been synthesized by the reaction of the new copper(I) trimethylsilylchalcogenolate compounds [(CAACCy)CuESiMe3] with ligand-supported group 11 acetates. The clusters are emissive at 77 K in solution and the solid state, with emission colors that depend on the metal/chalcogen composition. Electronic structure calculations point to a common 3[(M++E2-)LCT] emissive state for the series.

Investigating the influence of a CrO42−/Cr2O72− template in the formation of a series of silver–chalcogenide clusters

A series of silver–chalcogenide clusters was synthesised based on CrO42−/Cr2O72− anion templates.

Applications of metal selenium/tellurium compounds in materials science

AbstractMetal chalcogenides are technologically important materials. Physical, chemical, electrical and mechanical properties of these materials can be fine-tuned by manipulating their shape, size and composition. Although several methods are employed for their synthesis, single-source molecular precursor route has emerged as a versatile strategy for their synthesis and in controlling shape, size and composition of the material under moderate conditions. This chapter gives a brief coverage on the design and development of single-source molecular precursors which have been employed for the preparation of metal selenide/telluride nanocrystals and for deposition of thin films. The discussion includes synthesis of transition-, main group and f-block metal chalcogenolate and/or chalcogenide clusters as precursors and their conversion into metal chalcogenides in the form of thin films and nanostructures. Precursors for ternary metal chalcogenides are also included.

Nanostructured Platinum-Free Catalysts of Oxygen Reduction based on Metal Chalcogenide Cobalt Clusters

Nanostructured catalysts were synthesized by deposition of cobalt selenide and telluride on highly dispersed carbon black from solutions of corresponding metal chalcogenide clusters. The catalysts were characterized by powder X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. The electroreduction of oxygen at these catalysts is accompanied by consumption of four electrons. The catalysts were shown to be tolerant to methanol.

Host–Guest Binding Hierarchy within Redox‐ and Luminescence‐Responsive Supramolecular Self‐Assembly Based on Chalcogenide Clusters and γ‐Cyclodextrin

AbstractInvited for the cover of this issue are Anton A. Ivanov, Mohamed Haouas, Stéphane Cordier, Pavel Abramov, Emmanuel Cadot, and co‐workers involved within the CLUSPOM‐CNRS International Laboratory, including the Nikolaev Institute of Inorganic Chemistry (Novosibirsk, Russia) University of Versailles Saint Quentin and University of Rennes 1 (France). The image has been designed by Mrs. Alice Gronier (UVSQ) from an original idea of Dr. Pavel Abramov (NIIC). The cover picture depicts redox and luminescent octahedral clusters [Re6Q8(CN)6]4− that interact through supramolecular host–guest process, with biocompatible macrocycles such as γ‐cyclodextrin. Read the full text of the article at 10.1002/chem.201802102.

The Largest Supertetrahedral Oxychalcogenide Nanocluster and Its Unique Assembly.

Supertetrahedral oxychalcogenide T n nanoclusters (NCs, n denotes the number of metal-chalcogen layers) integrate chemically distinct but ordered oxygen and chalcogen sites in zinc-blend-type "quantum dots". They therefore offer a new level of control over various properties of semiconducting materials. So far, few such structures are known, and the cluster size is also limited to only T4 with 20 metal sites. Herein, we report an unusual oxysulfide T5 nanocluster with 35 metal sites. It has unprecedented In-O@In-S "core-shell" nanostructure and is also the largest supertetrahedral oxychalcogenide NC. Through cocrystallization, we further demonstrate that such oxychalcogenide NCs can be assembled to form multidimensional structures. In addition to N-donor imidazolates that help to form a 3-D structure with chiral quartz net, the O-donor benzenetricarboxylate (BTC) has also been found to successfully organize such T5 NCs. It is worth noting that no carboxylate ligands have been shown earlier for assembling chalcogenide clusters, despite their prevalence in MOFs. Given the wide availability of O-donor ligands, this work introduces a versatile platform with promise for a new generation of semiconducting inorganic-organic hybrid materials.

Host-Guest Binding Hierarchy within Redox- and Luminescence-Responsive Supramolecular Self-Assembly Based on Chalcogenide Clusters and γ-Cyclodextrin.

Water-soluble salts of anionic [Re6 Q8 (CN)6 ]4- (Q=S, Se, Te) chalcogenide octahedral rhenium clusters react with γ-cyclodextrin (γ-CD) producing a new type of inclusion compounds. Crystal structures determined through single-crystal X-ray diffraction analysis revealed supramolecular host-guest assemblies resulting from close encapsulations of the octahedral cluster within two γ-CDs. Interestingly, nature of the inner Q ligands influences strongly the host-guest conformation. The cluster [Re6 S8 (CN)6 ]4- interacts preferentially with the primary faces of the γ-CD while the bulkier clusters [Re6 Se8 (CN)6 ]4- and [Re6 Te8 (CN)6 ]4- exhibit specific interactions with the secondary faces of the cyclic host. Furthermore, analysis of the crystal packing reveals additional supramolecular interactions that lead to 2D infinite arrangements with [Re6 S8 (CN)6 ]4- or to 1D "bamboo-like" columns with [Re6 Se8 (CN)6 ]4- and [Re6 Te8 (CN)6 ]4- species. Solution studies, using multinuclear NMR methods, ESI-MS and Isothermal titration calorimetry (ITC) corroborates nicely the solid-state investigations showing that supramolecular pre-organization is retained in aqueous solution even in diluted conditions. Furthermore, ITC analysis showed that host-guest stability increases significantly ongoing from S to Te. At last, we report herein that deep inclusion alters significantly the intrinsic physical-chemical properties of the octahedral clusters, allowing redox tuning and near IR luminescence enhancement.

(PPh3)4Pt2S2(SnCl)]+: A Pt‐Sn‐S Cluster with a Ternary Trigonal Bipyramidal Cluster Core

By reaction of the organotin sulfide cluster [(R1Sn)4S6] (A) [R1 = CMe2CH2CMeN–N=CH(C11H8N2)] with [Pt(PPh3)2Cl2], a new heterobimetallic platinum‐tin chalcogenide cluster was synthesized with a ternary, trigonal bipyramidal cluster core. The structure of [(PPh3)4Pt2S2(SnCl)][SnCl3] (1) was determined by X‐ray diffraction, further characterization was done by means of electrospray ionization mass spectrometry (ESI‐MS) and nuclear magnetic resonance (NMR) spectroscopy.

Intercalation without altercation

Building materials with clusters instead of atoms promises unconventional properties, but those 'superatomic solids' are often too fragile to manipulate. Now, intercalating a guest within an ionic layered solid made of fullerenes and metal chalcogenide clusters greatly alters its conductivity and optical properties without disrupting its crystalline structure.

A N-Heterocyclic Carbene-Stabilized Coinage Metal-Chalcogenide Framework with Tunable Optical Properties.

A new class of coinage-metal chalcogenide compounds [Au4M4(μ3-E)4(IPr)4] (M = Ag, Au; E = S, Se, Te) has been synthesized from the combination of N-heterocyclic carbene-ligated gold(I) trimethylsilylchalcogenolates [(IPr)AuESiMe3] and ligand-supported metal acetates. Phosphorescence is observed from these clusters in glassy 2-methyltetrahydrofuran and in the solid state at 77 K, with emission energies that depend on the selection of metal/chalcogen ion composition. The ability to tune the emission is attributed to electronic transitions of mixed ligand-to-metal-metal-charge-transfer (IPr → AuM2) and interligand (IPr → E) phosphorescence character, as revealed by time-dependent density functional theory computations.N-heterocyclic carbenes (NHCs) have been applied as ancillary ligands in the synthesis of luminescent gold(I) chalcogenide clusters and this approach allows for unprecedented selectivity over the metal and chalcogen ions present within a stable octanuclear framework.

Room-temperature current blockade in atomically defined single-cluster junctions.

Fabricating nanoscopic devices capable of manipulating and processing single units of charge is an essential step towards creating functional devices where quantum effects dominate transport characteristics. The archetypal single-electron transistor comprises a small conducting or semiconducting island separated from two metallic reservoirs by insulating barriers. By enabling the transfer of a well-defined number of charge carriers between the island and the reservoirs, such a device may enable discrete single-electron operations. Here, we describe a single-molecule junction comprising a redox-active, atomically precise cobalt chalcogenide cluster wired between two nanoscopic electrodes. We observe current blockade at room temperature in thousands of single-cluster junctions. Below a threshold voltage, charge transfer across the junction is suppressed. The device is turned on when the temporary occupation of the core states by a transiting carrier is energetically enabled, resulting in a sequential tunnelling process and an increase in current by a factor of ∼600. We perform in situ and ex situ cyclic voltammetry as well as density functional theory calculations to unveil a two-step process mediated by an orbital localized on the core of the cluster in which charge carriers reside before tunnelling to the collector reservoir. As the bias window of the junction is opened wide enough to include one of the cluster frontier orbitals, the current blockade is lifted and charge carriers can tunnel sequentially across the junction.

Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases

The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4]4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m2·g–1 (NaYSnS4), 479 m2·g–1 (NaGdSnS4), and 354 m2·g–1 (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSnS4: 921 mg·g–1; and NaTbSnS4: 645 mg·g–1) and high selectivity for gases (CO2/H2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption‐based gas or hydrocarbon separation processes.

A Strong Donor-Acceptor System Based on a Metal Chalcogenide Cluster and Porphyrin.

Although great progress has been made for charge transfer (CT) compounds of various organic donor-acceptor systems, no CT compounds containing both inorganic chalcogenide cluster anions and organic porphyrin cations have been reported. Herein, a germanium chalcogenide cluster (Ge4S104-) is chosen as an electron donor and a methylated tetrakis(4-pyridyl)porphyrin (5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin, TMPyP) is selected as an electron acceptor to create chalcogenide cluster-porphyrin CT compounds (TMPyP-Ge4S10)·5H2O (1) and (MnTMPyP-Ge4S10)·13H2O (2). Their crystal structures have been characterized by single-crystal X-ray diffraction. Compound 1 is an ionic CT salt assembled through interion interactions, and compound 2 is a neutral CT dyad formed by metal-ligand axial coordination of the chalcogenide cluster with manganese porphyrin. The strong charge transfer properties are revealed by electronic spectra, theoretical calculations, 1H NMR, and ESR. The CT intensity of the chalcogenide cluster-porphyrin system can be modulated by metalation. The fluorescence and photocurrent response properties of 1 and 2 are related to the CT intensity.

Hydroxylated phosphines as ligands for chalcogenide clusters: self assembly, transformations and stabilization

Abstract This contribution is a documentation of recent advances in the chemistry of chalcogenide polynuclear transition metal complexes coordinated with mono- and di-phosphines functionalized with hydroxo groups. A survey of complexes containing tris(hydroxymethyl)phosphine (THP) is presented. The influence of the alkyl chain in bidentate phosphines, bearing the P–(CH2)x–OH arms, is also analyzed. Finally, isolation and structure elucidation of the complexes with HP(OH)2, P(OH)3, As(OH)3, PhP(OH)2, stabilized by coordination to Ni(0) and Pd(0) centers embedded into chalcogenide clusters, is discussed.

Superpolyhedron-Built Second Harmonic Generation Materials Exhibit Large Mid-Infrared Conversion Efficiencies and High Laser-Induced Damage Thresholds

Developing excellent infrared nonlinear optical (NLO) materials is challenging because of the incompatibility between a large second harmonic generation (SHG) efficiency and a high laser-induced damage threshold (LIDT). Here, we report three NLO chalcogenides, namely, Na2In4SSe6 (1), NaGaIn2Se5 (2), and NaIn3Se5 (3), whose crystal structures consist of supertetrahedral, superpentahedral, and superoctahedral chalcogenide clusters. Importantly, they exhibit SHG responses 7.0-, 2.1-, and 0.3-fold larger than and LIDTs 5.8-, 6.4-, and 10.7-fold higher than those of AgGaS2, respectively, almost achieving balance between large SHG efficiencies and high LIDTs. Theoretical calculations and structural analysis reveal that the enhanced SHG responses can be attributed to the superpolyhedral chalcogenide clusters. The high LIDTs can be ascribed to their small thermal expansion anisotropy. These findings may provide useful insights into the development of infrared NLO materials with superpolyhedron-built structures.

Metal Chalcogenide Clusters with Closed Electronic Shells and the Electronic Properties of Alkalis and Halogens.

Clusters with filled electronic shells and a large gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are generally energetically and chemically stable. Enabling clusters to become electron donors with low ionization energies or electron acceptors with high electron affinities usually requires changing the valence electron count. Here we demonstrate that a metal cluster may be transformed from an electron donor to an acceptor by exchanging ligands while the neutral form of the clusters has closed electronic shells. Our studies on Co6Te8(PEt3)m(CO)n (m + n = 6) clusters show that Co6Te8(PEt3)6 has a closed electronic shell and a low ionization energy of 4.74 eV, and the successive replacement of PEt3 by CO ligands ends with Co6Te8(CO)6 exhibiting halogen-like behavior. Both the low ionization energy Co6Te8(PEt3)6 and high electron affinity Co6Te8(CO)6 have closed electronic shells marked by high HOMO-LUMO gaps of 1.24 and 1.39 eV, respectively. Further, the clusters with an even number of ligands favor a symmetrical placement of ligands around the metal core.