(Cs₆Cl)₆Cs₃[Ga₅₃Se₉₆]: A Unique Long Period-Stacking Structure of Layers Made from Ga₂Se₆ Dimers via Cis or Trans Intralayer Linking

Abstract

The new compound (Cs6Cl)6Cs3[Ga53Se96] with its own structure type has been discovered by high-temperature solid-state reactions. The compound features a unique long period-stacking structure of layers that are built by the commonly observed dimeric Ga2Se6 unit extending in cis or trans intralayer linking. Single-crystal X-ray diffraction analyses show the trigonal space group R3̅m (No. 166) and a = 11.990(5) Å, c = 50.012(4) Å, and V = 6226.5(6) Å(3). The UV-vis-near-IR spectrum reveals a wide band gap of 2.74 eV that agrees well with the electronic structure calculation.

Large Second-Harmonic Generation Responses Achieved by the Dimeric [Ge2Se4(μ-Se2)]4– Functional Motif in Polar Polyselenides A4Ge4Se12 (A = Rb, Cs)

“…The Se–Se bond lengths ranging from 2.350(1) Å to 2.356(1) Å, are consistent with those in Cs 2 SnAs 2 Q 9 (Q = S, Se), APSe 5 (A= K, Rb) and A 2 P 2 Se 5 (A= Rb, Cs) . In addition, the coordination circumstances of Rb + and Cs + are shown in Figure S3 with atom distances marked, and the Rb (and Cs)–Se distances are also reasonable …”

Tunable Salt-Inclusion Chalcogenides for Ion Exchange, Photoluminescence, and Scintillation

“…We can make general observations based on the data in Tables S10 and S11, which suggest that Ga Q 4 -based SICs with 0D X Cs 6 units form when a Cs X salt is used in the reaction without the addition of Ba metal. ,, In contrast, the use of a Ba-only based flux stabilizes X Ba 4 ( X = F and Cl) tetrahedra or X Ba 6 ( X = Cl, Br, and I) octahedra that form 2D or 3D salt-inclusion moieties. ,,,− , The formation of other salt-inclusion building blocks is possible when the flux contains only A cations ( A = Na and K) − or a combination of Ba and A metal ( A = Li, K, Rb, and Cs). − ,, In summary, for the GaQ 4 -based SIC materials, we find that flux, salt-inclusion, and framework building blocks all influence the phase formation of SICs, illustrating how complex the synthesis of SICs is.…”

“…Multiple parameters affect the formation of SICs, e.g., the halide salt, the framework building block, the temperature profile, and the choice of flux. To better understand the formation of Ga Q 4 -based SICs, we analyzed the 39 reported Ga Q 4 -based frameworks. − ,,,,,,− The data in Tables S10 and S11 reveal that polychalcogenide flux crystal growth can be successfully coupled with halide fluxes to obtain single crystals of SICs. The polychalcogenide flux, over a wide range of temperatures, appears to increase the solubility and reactivity of the chalcogenide reagents and intermediates, consistent with hard-soft principles .…”

“…A recent review of SICs by Lin et al highlighted that the asymmetric Ga Q 4 polyhedron is one of the most common building blocks for SICs, where a typical Ga Q 4 -based SIC framework consists of Ga Q 4 , pseudo-T 2 Ga 4 Q 10 or M Ga 3 Q 10 supertetrahedral units. The related Ga 3 Q 9 building block is less common, and only a few examples of it have been reported to date, including [LiCs 2 Cl]­LiGa 3 S 6 , [Cs 6 Cl] 6 Cs 3 Ga 53 Se 96 , and [Cs 6 Cl]­GeGa 5 Q 12 ( Q = S and Se, Figure S1). The exploration of new Ga Q 4 -based SIC materials is of interest to better understand the stabilization principles of non-typical Ga Q 4 arrangements, such as those of Ga 3 Q 9 units.…”

CsBi4Te6: a new facile synthetic method and mid-temperature thermoelectric performance

“…Similar phenomena were also reported in the previous literature by our group. [11][12][13] The TE properties have been analyzed on the hot-pressed polycrystalline pellet of the as-synthesized CsBi 4 Te 6 . The obtained pellets had relative densities not less than 98% of the theoretical value (7.18 g cm −3 ).…”