Synthesis and Structural Characterization of Cs₂Ga₂Se₅

Abstract

Cs2Ga2Se5 was obtained by the reaction of CsN3 with stoichiometric amounts of GaSe and Se at elevated temperature. It forms yellow crystals embedded in a pure orange microcrystalline powder. The crystal structure of Cs2Ga2Se5 was determined by single‐crystal X‐ray diffraction at 123 K. The compound crystallizes monoclinically in the space group C2/c (No. 15) with a = 15.3911(5) Å, b = 7.3577(2) Å, c = 12.9219(3) Å, β = 126.395(3)°, V = 1177.89(7) Å3, and Z = 4. The structure features one‐dimensional chains 1∞[Ga2Se3(Se2)2–], consisting of edge‐ and corner sharing GaSe4 tetrahedra. Raman spectroscopic measurements reveal vibrational bands of the Se22– units at 236 cm–1, and the bands of Ga–Se vibrations at 254 and 273 cm–1. UV/Vis diffuse reflectance spectroscopy shows the bandgap at about 1.95 eV.

Synthesis, Structural Characterization, and Physical Properties of Cs2Ga2S5, and Redetermination of the Crystal Structure of Cs2S6

“…Distances between the gallium atom and the disulfide ions are longer than those to the sulfide ions, as already observed in CsGaQ 3 (Q = S, Se) [5,21] and Cs 2 Ga 2 Se 5 . [8] The S-Ga-S angles range from 100.77(6) to 117.81 (7)8. The observed bond lengths and angles are in good agreement with those reported for similar compounds.…”

“…The recently reported compounds Cs 2 Ga 2 Se 5 , [8] [C 6 H 16 N 2 ] [In 2 Se 3 (Se 2 )], [9] [M(C 12 H 8 N 2 ) 3 ] [In 2 Se 3 (Se 2 )]H 2 O (M= Ni, Fe), [10] [C 4 H 14 N 2 ][Ga 2 Se 3 (Se 2 )], [11] [C 6 H 16 N 2 ][Ga 2 Se 3 (Se 2 )], [12] and [Mn(C 2 H 8 N 2 ) 3 ][In 2 Se 3 (Se 2 )] [13] contain analogous chains…”

“…1 with a = 4.658(1), b = 9.174(1), c = 11.537(1) ; a = 84.842 (8), b = 84.810 (7), g = 89.240(8)8; V = 488.99(8) 3 ; Z = 2 (293 K, single-crystal data) and a = 4.669(1), b = 9.211(1), c = 11.550(5) ; a = 84.69(2), b = 84.81(2), g = 89.17(3)8; V = 492.5(4) 3 (293 K, powder data). The crystal structure was solved by charge-flipping methods with SUPER-FLIP, [19] implemented in Jana2006, [20] and refined to R 1 = 0.0326 and wR 2 = 0.0647 (for all data) by full-matrix least squares methods with Jana2006.…”

Synthesis and Crystal Structures of Rb4Al2S5 and Cs4In2S5

“…For ternary chalcogenogallates characteristic structural features are also 1D strands,18 2D layers, isolated [Ga 2 Q 6 ] double tetrahedra,19 and the hexameric anion in Cs 10 Ga 6 Se 14 18. Recently, a new structure motif was observed in Cs 2 Ga 2 Q 5 ( Q = S, Se), which contains 1 ∞ [ T 2 Q 3 ( Q 2 ) 2– ] anionic chains with dichalcogenide units substituting single chalcogenide ions 20,21…”

In Situ X-ray Diffraction Study of the Thermal Decomposition of Selenogallates Cs2[Ga2(Se2)2–xSe2+x] (x = 0, 1, 2)

“…The crystal structures of CsGaSe 3 , 4 Cs 2 Ga 2 Se 5 , 7 and CsGaSe 2 -mC16 20,21 feature polymeric, anionic chalcogenogallate chains…”