Synthesis, Structure, Multiband Optical, and Electrical Conductive Properties of a 3D Open Cubic Framework Based on [Cu8Sn6S24]z− Clusters

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.

Sodium-Stuffed Open-Framework Quaternary Chalcogenide Built with (Cu2Ga6S18)16- Ribbons Cross-Linked by Unusual Linear Cu(I) Pillars

A quaternary compound, Na₁₅Cu₃Ga₆S₁₈, the first member in the A-Cu-Ga-S (A = alkali metal) series, has been synthesized from a solid-state metathesis reaction between Na₆Ga₂S₆ and CuCl as well as from a combination of Na₂S, Ga, Cu, and S. The compound crystallizes in a monoclinic crystal system, space group C2/c, and represents a unique open-framework structure with channels filled with eight crystallographically distinct Na ions. The anionic framework is built up of infinite chains of corner-shared GaS₄ tetrahedra fused together by an edge-shared dimer of CuS₄ tetrahedra forming one-dimensional ribbons of (Cu₂Ga₆S₁₈)^16-, which are cross-linked by linearly coordinated S-Cu-S linkages resulting in a three-dimensional network with tunnels filled with Na atoms. Optical band gap measurements show that the compound has a direct band gap of 3.00 eV that is in good agreement with the theoretical band gap derived from density functional theory calculations. Band structure calculations further indicate that the states near the Fermi level are dominated by tetrahedral Cu⁺(d) and S(p) states resulting from the antibonding interactions, while s-d hybridization is prevalent in linear Cu⁺ coordination. Ionic conductivity measurements show that the compound has a room-temperature Na ion conductivity of 2.72 × 10^-5 mS/cm with an activation energy of 0.68 eV, which corroborates well the nudged elastic band calculations.

Syntheses, structures, and photocatalytic properties of open-framework Ag-Sn-S compounds

Four open-framework Ag-Sn-S compounds K2Ag2Sn2S6 (1); K2Ag2SnS4 (2); Rb2Ag2SnS4 (3); and Cs2Ag2SnS4 (4) have been synthesized using a solvothermal method. Compound 1 possesses a unique three-dimensional (3D) structure in which Ag+ ions are two-coordinated. Compounds 2-4 have the same layered structure in which Ag+ ions are tetrahedrally coordinated. Photocatalytic degradation properties of methylene blue have been investigated and compound 1 displays excellent photodegradation activities. The photoelectric response properties, optical properties, and theoretical calculations of these compounds have also been studied.

Alcohol-solvothermal syntheses, crystal structures and photocatalytic properties of tin selenides with polyselenide ligands

New polyselenidostannates with Se₂²⁻ or Se₄²⁻ polyselenide ligands, [TM(en)₃]Sn₃Se₆(Se₂) (1–3), [Ni(en)₃]Sn₃Se_7.5 (4) and [TM(en)₃][Sn(Se₄)₃] (5–8), were prepared by alcohol-solvothermal methods.

Highly open chalcogenide frameworks built from unusual defective supertetrahedral clusters

Two highly open chalcogenide frameworks built from unusual supertetrahedral SBUs.

PCU-type copper-rich open-framework chalcogenides: pushing up the length limit of the connection mode and the first mixed-metal [Cu7GeSe13] cluster

A pure dimeric connection mode and an unprecedented Cu₇GeSe₁₃ cluster were found in a series of pcu-type copper-rich open-framework chalcogenides.

Synthesis, crystal structure and physical properties of FeV4S8and KFe2V8S16

Two compounds with the formulae FeV₄S₈and KFe₂V₈S₁₆were successfully synthesizedviaa melting salt method.

A novel copper-rich open-framework chalcogenide constructed from octahedral Cu4Se6 and icosahedral Cu8Se13 nanoclusters

A unique open-framework chalcogenide was constructed from two kinds of cluster-based secondary building units (SBUs), namely, the icosahedral Cu₈Se₁₃ cluster and the octahedral Cu₄Se₆ cluster.

Synthesis, crystal structure, electronic structure, and photoelectric response properties of KCu2SbS3

A new layered compound KCu₂SbS₃ was synthesized via a facile reactive flux method. The compound, whose crystal structure features [Cu₂SbS₃]⁻ layers packing along [001], possesses a direct-transition band gap of 1.7 eV. Photoelectric measurement demonstrates the potential for applications in photovoltaic devices.