Topological Transformation and Dimensional Reduction in Multicomponent Metal-Organic Frameworks for Gas Separations.

Multicomponent MOFs have offered a wide range of opportunities to harness new properties. However, the synthesis of multicomponent MOFs remains challenging. This work demonstrates the synthesis of a family of multicomponent MOFs by topological transformation from well-established multicomponent partitioned acs (pacs) structures.

Stable Microporous Metal-Organic Framework Based on Tritopic Pyrazolate Ligand for Xe/Kr Separation.

Pyrazolate ligands, renowned for their potent electron-donating capabilities, have emerged as promising building blocks for the construction of stable metal-organic frameworks (MOFs) particularly when paired with late transition metals. While a plethora of diverse MOFs have been meticulously crafted using ditopic pyrazolate ligands, the realm of multidentate pyrazolate-based MOF structures remains relatively unexplored. This research unveils a notable achievement in the synthesis of a novel three-dimensional microporous MOF, characterized by its single-crystal form, meticulously assembled from a tritopic pyrazole ligand and cobalt ions.

One ligand, two roles: novel pillar-layered metal-organic frameworks built with a 3D ligand and asymmetric inorganic nodes.

Herein, we show two cases of pillar-layered MOFs which are built solely with one kind of three-dimensional (3D) ditopic ligand. The ligand in both structures functions not only as an intralayer linker in the layer but also as a "pillar" between adjacent layers. Such multi-functionality of the linker is accompanied by uncommon asymmetric 10- metal hexamer or 7- tetramer nodes, which have never been reported in previous 3D MOF structures.

Six-Membered Ring Directed Assembly of a Zirconium Zeolitic Metal-Organic Framework for Efficient Separation of Hexane Isomers.

The synthesis of zirconium MOFs with zeolite net is quite challenging due to the high connectivity of Zr clusters, which is far from tetrahedral connection, a requisite for zeolite net. In this work, we demonstrate a six-membered ring (6MR) strategy through mimicking of mineral zeolites with mixed ditopic and tritopic carboxylate linkers. With this strategy, the ditopic linker cross-links Zr clusters to form 4-connected zeolite-like nets, while the tritopic one is used to direct the formation of 6MR and simultaneously consumes extra coordination sites on the cluster.

A hierarchical CoS/Ni(OH) heterostructure as a bifunctional electrocatalyst for urea-assisted energy-efficient hydrogen production.

We report hierarchical CoS/Ni(OH)/NF heterostructure nanorod arrays, which manifest superior bifunctional catalytic activities for the HER and UOR due to amorphous Ni(OH), synergistic effect of multiple components and self-supported structure. The CoS/Ni(OH)/NF-based urea electrolyzer requires a low cell voltage of 1.485 V to deliver 10 mA cm, which is obviously lower than that needed in water electrolysis.

New crystalline 1D/2D/3D indium selenides directed by piperidine and auxiliary solvents.

The construction of cluster-based crystalline chalcogenide structures through the traditional solvothermal method relies on synergistic control of precursors, template cations and auxiliary solvents. Generally, the combination of metal precursors plays a crucial role in controlling the size of clusters, while organic templates and auxiliary solvents usually contribute to the type of clusters and architecture of the framework. Decades of synthetic efforts have been mainly devoted to expanding organic amine templates for constructing new structures.

Controllable incorporation of 1,2,4-triazolate into cluster-based metal-chalcogenide frameworks.

The first incorporation of the 1,2,4-triazolate ligand into metal-chalcogenide semiconductor frameworks resulted in the formation of two new supertetrahedral-cluster-based triazolate frameworks (SCTFs) with hybrid inter-cluster connection modes, namely, SCTF-1 with an inorganic/organic linker ratio of 3 : 1 and SCTF-2 with a linker ratio of 2 : 2. The optical properties of these two close models were investigated.

Two Copper-Rich Open-Framework Chalcogenides Built from Unusual [Cu(SnM)Se] Clusters and [(SnM)Se] Dimeric Linkers (M = In and Ga).

Reported here are two unprecedented copper-rich open-framework chalcogenides constructed from unusual [Cu(SnM)Se] clusters and [(SnM)Se] dimeric linkers (M = In and Ga). The photoresponsive properties in the IR range and the photocatalytic activity for degradation of methylene blue dye of these two isostructural semiconductors were proved to be effectively adjusted by trivalent metal ions in a cluster.

Enhanced Water Dispersibility of Discrete Chalcogenide Nanoclusters with a Sodalite-Net Loose-Packing Pattern in a Crystal Lattice.

Good aqueous dispersibility of metal chalcogenide nanoclusters with an atomically precise structure is desirable to achieve tiny and uniform cluster-based "quantum dots". However, there are big challenges toward this goal, especially for the large-sized nanoclusters without covalently bonded organic ligands, because the strong electrostatic interactions between closely packed negatively charged nanoclusters and protonated organic amine templates in the crystal lattice impede the dispersion of cluster-based bulk crystalline samples. Here, we report two iso-structured crystalline metal chalcogenides composed of discrete supertetrahedral T4-MInS nanoclusters with the formulas of [MInS] (denoted M, M = Zn and Fe), which adopt a sodalite-net loose-packing pattern in the crystal lattice and display superior dispersibility in water and some organic solvents as compared to other cases composed of the same type of nanoclusters with close-packing pattern.

Direct observation of charge transfer between molecular heterojunctions based on inorganic semiconductor clusters.

A deep understanding of the dynamics of photogenerated charge carriers is extremely important for promoting their germination in semiconductors to enhance the efficiency of solar energy conversion. In contrast to that of organic molecular heterojunctions (which are widely employed in organic solar cells), the charge transfer dynamics of purely inorganic molecular heterojunctions remains unexplored. Herein, we reveal the dynamics of charge transfer between inorganic semiconductor molecular heteroclusters by selecting a group of open-framework metal chalcogenides as unique structure models constructed from supertetrahedral ([InS]) and ([MInS], M = Mn or Fe) clusters.

New Insights into Mn-Mn Coupling Interaction-Directed Photoluminescence Quenching Mechanism in Mn-Doped Semiconductors.

Strong Mn-Mn coupling interactions (dipole-dipole and spin-exchange), predominantly determined by statistically and apparently short Mn···Mn distances in traditional heavily Mn-doped semiconductors, can promote energy transfer within randomly positioned and close-knit Mn pairs. However, the intrinsic mechanism on controlling Mn emission efficiency is still elusive due to the lack of precise structure information on local tetrahedrally coordinated Mn ions. Herein, a group of Mn-containing metal-chalcogenide open frameworks (), built from [MnInS] nanoclusters (denoted T4-MnInS) with a precise [MnS] configuration and length-variable linkers, were prepared and selected as unique models to address the above-mentioned issues.

Hierarchical heterostructure of SnO confined on CuS nanosheets for efficient electrocatalytic CO reduction.

The direct electroreduction of CO2 to ratio-tunable syngas (CO + H2) is an appealing solution to provide important feedstocks for many industrial processes. However, low-cost, Earth-abundant yet efficient and stable electrocatalysts for composition-adjustable syngas have still not been realized for practical applications. Herein, new hierarchical 0D/2D heterostructures of SnO2 nanoparticles (NPs) confined on CuS nanosheets (NSs) were designed to enable CO2 electroreduction to a wide-range syngas (CO/H2: 0.

Molecular Modulation of a Molybdenum-Selenium Cluster by Sulfur Substitution To Enhance the Hydrogen Evolution Reaction.

Many strategies to optimize molybdenum selenide based electrocatalysts for hydrogen evolution reaction (HER) have been explored; however, the modulation of molybdenum selenide on the molecular scale remains an ongoing challenge. Here, we synthesized a new molecular HER electrocatalyst based on a molybdenum-selenium cluster () and further realized its modulation by precise sulfur substitution at the molecular level to enhance the HER activity. The density functional theory (DFT) calculations demonstrated that the substituted sulfur could promote the hydrogen adsorption process and thus improve the HER performance.

Highly open chalcogenide frameworks built from unusual defective supertetrahedral clusters.

Enlarging the openess of chalcogenide frameworks is of significance for functionalizing semiconducting open frameworks, which are usually limited by their own interpenetration due to the rigid clusters and monotonous linkers. Herein, we report two zeolite-like chalcogenide open frameworks constructed from unusual defective supertetrahedral clusters and various kinds of linkers. Both the structures exhibit impressive architecture and high extra-framework volume ratios.

Light-triggered evolution of molecular clusters toward sub-nanoscale heterojunctions with high interface density.

Herein, we report a simple, yet highly effective approach for constructing a new type of sub-nanoscale ZnS/ZnO heterojunction (∼2-4 nm) with highly rich interfaces by photoetching hybrid Zn-S-O molecular clusters. The obtained ZnS/ZnO heterojunctions with ZnS spheres decorated with ultrasmall amorphous ZnO dots exhibit superior photocatalytic performance (∼94.0 μmol g h), compared to nanoscale homologous samples obtained via conventional heat treatment (∼17.

Three new metal chalcogenide open frameworks built through co-assembly and/or hybrid assembly from supertetrahedral T5-InOS and T3-InS nanoclusters.

Reported here are three new metal chalcogenide open frameworks built from supertetrahedral [InSO] (denoted as T5-InOS or o-T5) and [InS] (denoted as T3-InS) nanoclusters of different sizes and compositions via co-assembly and/or hybrid assembly modes. Such a set of cluster-based superlattices with dia topological structures clearly exhibit quantum size effects and electronic coupling interaction of adjacent nanoclusters, which can effectively explain that the band gap of the T3-(o-T5) hybrid-assembled material lies in the middle of T3-T3 and (o-T5)-(o-T5) co-assembled materials.

Two Penta-Supertetrahedral Cluster-Based Chalcogenide Open Frameworks: Effect of the Cluster Spatial Connectivity on the Electron-Transport Efficiency.

High-degree connectivity of clusters in open-framework chalcogenide semiconductors conceptually facilitates electron mobility between clusters; however, no direct evidence was obtained to prove the prediction because of the shortage of suitable structure models among such systems. Herein, two open-framework chalcogenides built from the same types of heterometallic P2-CuInSnS clusters but with different spatial connectivities of clusters were obtained, in which 3-connected clusters are assembled into a 3D framework with SrSi topology (MCOF-1) and 4-connected clusters (μ-P2) are arranged into diamond topology (MCOF-2). Compared to MCOF-1, MCOF-2 exhibits a relatively rapid photocurrent response, good reproducibility, and high electrocatalytic oxygen reduction reaction activity.

Three-Dimensional Superlattices Based on Unusual Chalcogenide Supertetrahedral In-Sn-S Nanoclusters.

Reported here are two novel metal chalcogenide superlattices built from unusual supertetrahedral TO2-InSnS clusters. With regard to only one previously reported case of a TO2-InS-based 2D-layered structure, such a combination of In-Sn-S components is thought to be reasonable for leading to the first observation of 3D superlattices based on TO2-InSnS clusters. Besides, these title semiconducting materials also display good performance on the electrocatalytic oxygen reduction reaction.

A semiconducting metal-chalcogenide-organic framework with square-planar tetra-coordinated sulfur.

We demonstrated here a novel semiconducting metal-chalcogenide-organic framework (MCOF-89) with an optical bandgap through the unlikely assembly between a metal chalcogenide unit and carboxylic acid. The elusive metal-chalcogenide unit [Mn(μ-S)] with square-planar tetra-coordinated sulfur (sptS) is for the first time observed in MOFs.

Stable Supersupertetrahedron with Infinite Order via the Assembly of Supertetrahedral T4 Zinc-Indium Sulfide Clusters.

A new family member of T p, q-based hierarchical chalcogenide architecture was created by assembling regular T4-ZnInS clusters into a periodically "hollowed-out" cubic ZnS-type structure framework (T4,∞) via the cross-linker of the tetracoordinated corner μ-S. Ion-exchange and CO adsorption experiments suggest that such a structure with a corner μ-S linker has structural stability superior to those of previously reported chalcogenide open frameworks composed of the same T4-ZnInS clusters with a bicoordinated (μ-S) or a tricoordinated (μ-S) cross-linker. Importantly, this case further demonstrates the feasibility of systematically engineering stable porous crystalline chalcogenide frameworks by a "hollow-out" strategy.

Metal Chalcogenide Imidazolate Frameworks with Hybrid Intercluster Bridging Mode and Unique Interrupted Topological Structure.

Constructing a hybrid connection mode between cluster-based building blocks is of particular importance in the pursuit of fascinating framework structures. Reported here are two new metal chalcogenide imidazolate frameworks (SCIF-11 and SCIF-12) with a hybrid intercluster bridging mode and a unique interrupted topological structure. SCIF-11 has a typical dia topology with a T3-InS supertetrahedral cluster as the node and an imidazolate (IM) ligand as the linker, but it for the first time combines two kinds of intercluster connecting modes: T3-S-T3 and T3-IM-T3.

Hybrid Assembly of Different-Sized Supertetrahedral Clusters into a Unique Non-Interpenetrated Mn-In-S Open Framework with Large Cavity.

Reported here is a unique crystalline semiconductor open-framework material built from the large-sized supertetrahedral T4 and T5 clusters with the Mn-In-S compositions. The hybrid assembly between T4 and T5 clusters by sharing terminal μ-S is for the first time observed among the cluster-based chalcogenide open frameworks. Such three-dimensional structure displays non-interpenetrated diamond-type topology with extra-large nonframework volume of 82%.

Monodisperse Ultrasmall Manganese-Doped Multimetallic Oxysulfide Nanoparticles as Highly Efficient Oxygen Reduction Electrocatalyst.

The highly efficient and cheap non-Pt-based electrocatalysts such as transition-based catalysts prepared via facile methods for oxygen reduction reaction (ORR) are desirable for large-scale practical industry applications in energy conversion and storage systems. Herein, we report a straightforward top-down synthesis of monodisperse ultrasmall manganese-doped multimetallic (ZnGe) oxysulfide nanoparticles (NPs) as an efficient ORR electrocatalyst by simple ultrasonic treatment of the Mn-doped Zn-Ge-S chalcogenidometalate crystal precursors in HO/EtOH for only 1 h at room temperature. Thus obtained ultrasmall monodisperse Mn-doped oxysulfide NPs with ultralow Mn loading level (3.

Nonlinear Variation in the Composition and Optical Band Gap of an Alloyed Cluster-Based Open-Framework Metal Chalcogenide.

Unexpected nonlinear variation in the composition and optical band gap was observed in an alloyed open-framework metal chalcogenide composed of supertetrahedral clusters. A tentative hypothesis was proposed to explain how the title compound [InSe(HO)]·24H-PR· nHO (PR = piperidine) exhibits a limitation in the S-alloying level and a large variation in the optical band gap.

A 3D neutral chalcogenide framework built from a supertetrahedral T3 cluster and a metal complex for the electrocatalytic oxygen reduction reaction.

Herein we report a new 3D neutral chalcogenide framework constructed by using a supertetrahedral T3 cluster ([MnGaSnS]) as the building unit and a metal complex ([Mn(dach)], dach = 1,2-diaminocyclohexane) as the linker. Significantly, the obtained material exhibits high-efficiency electrocatalytic oxygen reduction activity with quasi-four-electron transfer and a small Tafel slope, much better than that of commercial Pt/C (10 wt%).