Two new phases in the ternary RE–Ga–S systems with the unique interlinkage of GaS₄building units: synthesis, structure, and properties

Abstract

Two novel ternary rare-earth chalcogenides, YbGaS and LuGaS, have been prepared by solid-state reactions of an elemental mixture at high temperatures. Their structures were determined on the basis of single-crystal X-ray diffraction. YbGaS crystallizes in the monoclinic space group C2/m (no.12) [a = 23.557(2) Å, b = 3.7664(4) Å, c = 12.466(1) Å, β = 90.915(9)°, V = 1105.9(2) Å and Z = 2], whereas LuGaS crystallizes in the triclinic space group P1[combining macron] (no.2) [a = 7.735(3) Å, b = 10.033(4) Å, c = 10.120(4) Å, α = 106.296(4)°, β = 100.178(5)°, γ = 101.946(3)°, V = 714.1(5) Å and Z = 2]. Both the structures feature complicated three dimensional frameworks with the unique interlinkages of GaS as basic building units. Significantly, photo-electrochemical measurements indicated that title compounds were photoresponsive under visible-light illumination. Furthermore, the UV-visible-near IR diffuse reflectance spectra, thermal stabilities, electronic structures, physical properties as well as a structure change trend of the ternary rare-earth/gallium/sulfur compounds have been evaluated.

One-Dimensional Chains in Pentanary Chalcogenides A2Ba3Cu2Sb2S10 (A = K, Rb, Cs) Displaying a Photocurrent Response

“…This result verified the potential application of Rb 2 Ba 3 Cu 2 Sb 2 S 10 as a photocatalyst for an electron-related photocatalytic reaction. Similar phenomena were found in some other inorganic chalcogenides, such as BaCuSbQ 3 (Q = S, Se), 20 Lu 5 GaS 9 , 38 and Yb 6 Ga 4 S 15 . 38 Moreover, theoretical calculations were also carried out to understand the interrelationship of the optical performance and electronic structure.…”

“…This result verified the potential application of Rb 2 Ba 3 Cu 2 Sb 2 S 10 as a photocatalyst for an electron-related photocatalytic reaction. Similar phenomena were found in some other inorganic chalcogenides, such as BaCuSbQ 3 (Q = S, Se), Lu 5 GaS 9 , and Yb 6 Ga 4 S 15 …”

Synthesis, Crystal Structure, and Properties of Three La–Zn–P Compounds with Different Dimensionalities of the Zn–P Framework

“…Indeed, no P–P homoatomic bonds were found in La 2 Zn 11 P 9 and La 3 Zn 2 P 4 , while P–P homoatomic bonds are abundant in the crystal structure of La 7 Zn 2 P 11 . Dimensionality reduction is an important concept to rationalize the composition–structure relationship of inorganic compounds, which is widely applied in chalcogenide chemistry, , especially in the diverse family of rare-earth containing chalcogenides. − The dimensionality reduction of La–Zn–P ternary system may affect physical properties of the reported compounds. Among all reported phases, we were able to produce single-phase samples for only one composition, namely, La 3 Zn 1.75 P 4 .…”

Rb2CuSb7S12: Quaternary Antimony-Rich Semiconductor Featuring a Three-Dimensional Open Framework and Exhibiting an Intriguing Photocurrent Response

“…So far, four types of structures are reported and given based on their different stoichiometries as follows: 1–1–2–4 type (i.e., RbCuSb 2 S 4 and CsCuSb 2 S 4 ), 1–2–1–3 type [i.e., ACu 2 SbS 3 (A = K, Rb, and Cs) and KCu 2 SbSe 3 ], 2–1–1–3 type (i.e., Na 2 CuSbS 3 and K 2 CuSbS 3 ), and 2–2–2–5 type (i.e., Rb 2 Cu 2 Sb 2 S 5 , Cs 2 Cu 2 Sb 2 S 5 , and Cs 2 Cu 2 Sb 2 Se 5 ). It is worth mentioning that the structure change trend of these compounds does not follow the previously reported inherent laws between the structural dimension and guest/host metal atom ratio. − For instance, RbCuSb 2 S 4 and KCu 2 SbS 3 show identical A/(Cu + Sb) ratios (i.e., 0.33), but the former possesses a 3D framework structure and the latter adopts a 2D-layered structure. Further structural analysis shows that the Cu/Sb ratio is the major determinant of structural dimension change (shown below).…”