Antimony-Assisted Assembly of Basic Supertetrahedral Clusters into Heterometallic Chalcogenide Supraclusters

Atomically precise metal chalcogenide supertetrahedral clusters: frameworks to molecules, and structure to function

Metal chalcogenide supertetrahedral clusters (MCSCs) are of significance for developing crystalline porous framework materials and atomically precise cluster chemistry. Early research interest focused on the synthetic and structural chemistry of MCSC-based porous semiconductor materials with different cluster sizes/compositions and their applications in adsorption-based separation and optoelectronics. More recently, focus has shifted to the cluster chemistry of MCSCs to establish atomically precise structure-composition-property relationships, which are critical for regulating the properties and expanding the applications of MCSCs. Importantly, MCSCs are similar to II-VI or I-III-VI semiconductor nanocrystals (also called quantum dots, QDs) but avoid their inherent size polydispersity and structural ambiguity. Thus, discrete MCSCs, especially those that are solution-processable, could provide models for understanding various issues that cannot be easily clarified using QDs. This review covers three decades of efforts on MCSCs, including advancements in MCSC-based open frameworks (reticular chemistry), the precise structure-property relationships of MCSCs (cluster chemistry), and the functionalization and applications of MCSC-based microcrystals. An outlook on remaining problems to be solved and future trends is also presented.

Stable 3D neutral gallium thioantimonate frameworks decorated with transition metal complexes for a tunable photocatalytic hydrogen evolution

Incorporating transition metal (TM) complexes into cluster-based chalcogenide frameworks is an effective synthetic strategy to induce structural diversity and control the optoelectronic properties, which may further improve their photocatalytic performance. However, limited studies have been conducted on frameworks constructed by TM complexes covalently bonded with supertetrahedral Tn clusters, let alone on their properties, especially photocatalytic H₂ activity. Herein, three new isostructural three-dimensional (3D) neutral inorganic-organic open frameworks of gallium thioantimonate comprised of thiogallate-based supertetrahedral T3 clusters that are covalently bonded with TM complexes ([TM(TEPA)]²⁺, TM = Mn/Ni/Fe, TEPA = tetraethylenepentamine) at the edges and are linked by single Sb³⁺ ions at the corner, namely, NCF-3-Mn/Ni/Fe have been solvothermally synthesized and structurally characterized, and display good thermal and chemical stability. Benefiting from an adjustable TM centre, the title compounds possess tunable photocatalytic H₂ evolution activity, among which NCF-3-Mn exhibits the highest photocatalytic activity probably due to its favourable band structure and enhanced carrier separation efficiency.

Consolidation of 2D Frameworks Based on Corner-Shared Supertetrahedral T5 Clusters via M2OS2 Units for Tunable Photoluminescent and Semiconductor Properties

Introducing transition metals into the intercluster linkers has been considered an important strategy for the rapid development of metal chalcogenide supertetrahedral (Tn) cluster-based open frameworks with excellent properties. However, using this strategy for achieving the structure and property tunability in the cluster-based framework of Tn (n ≥ 5) is still a great challenge. Herein, we report on three new sulfide and oxosulfide open frameworks of T5 clusters, i.e., T5-ZnMnInOS ([In₃₀Zn₅Mn₄O₂S₅₈]^12-), T5-MnInOS ([In₃₄Mn₅O₂S₅₈]^8-), and T5-MnInS ([In₂₈Mn₆S₅₄]^12-). Interestingly, transition metals Zn and Mn are successfully introduced into T5-ZnMnInOS and T5-MnInOS via the consolidation of corner-shared Zn₂OS₂ and Mn₂OS₂ units, respectively. Under the photoexcitation of UV light, three compounds can emit bright-orange-red light closely associated with the Mn²⁺ ions, and the compounds containing M₂OS₂ units exhibit better photoluminescence (PL) lifetimes. Variable-temperature PL spectra demonstrate that the introduced M₂OS₂ units are favorable for weakening the deformation of the skeleton structure and decreasing the red shifts of the emission peaks at low temperatures. Moreover, the experimental results exhibit that the three compounds are wide-band-gap semiconductors and that the photogenerated electron separation efficiency can be doubly increased because the intercluster linkers are fixed by the M₂OS₂ units. This work paves a new way for enriching the content and distribution types of transition-metal sites in the supertetrahedral cluster-based metal chalcogenide open frameworks.

A pillar-layered chalcogenide framework assembled by [Mn5S12N12]n layers and [Sb2S5] inorganic pillars

Reported here is an attractive pillar-layered metal chalcogenide open framework, in which [Sb₂S₅] building units act as pillars between [Mn₅S₁₂(N₂H₄)₆]_n layers. The obtained compound exhibits high stability in both acid and base media and good performance in the electrocatalytic oxygen reduction reaction (ORR).

A novel copper-rich open-framework chalcogenide with chiral topology constructed from distinctive bimetallic [Cu5SnSe10] clusters

Reported here is the first chiral copper-rich open-framework chalcogenide with a quartz (qtz) topology built on distinctive [Cu₅SnSe₁₀] clusters connected by [SnSe₄] bridging units. Through in situ sulfur doping, sulfurized compounds could be obtained that exhibit improved photocatalytic performance. This work expands the family of COCs with new building blocks and topologies and demonstrates the significance of chalcogen doping in COCs.