Cs₆Ga₂Se₆, ein ternäres Selenogallat(III) mit isolierten [Ga₂Se₆]^6--Ionen/Cs₆Ga₂Se₆, a Ternary Selenogallate(III) with Isolated [Ga₂Se₆]^6- Ions

Abstract

<jats:title>Abstract</jats:title><jats:p> Cs<jats:sub>6</jats:sub>Ga<jats:sub>2</jats:sub>Se<jats:sub>6</jats:sub> can be prepared from mixtures of Cs<jats:sub>2</jats:sub>Se and Ga<jats:sub>2</jats:sub>Se<jats:sub>3</jats:sub>. The transparent single crystals of the moisture sensitive compound (m.p. 685 °C) crystallize in the monoclinic system with a = 848.0(5), b = 1364.4(5), c = 1111.5(5) pm, β = 126.22(5)° (T = -150 °C, Z = 2, space group P2<jats:sub>1</jats:sub>/c). The gallium atoms pairwisely occupy selected tetrahedral holes between layers formed by the cesium and selenium ions. This structural principle leads to the formation of double tetrahedral isolated [Ga<jats:sub>2</jats:sub>Se<jats:sub>6</jats:sub>]<jats:sup> 6- </jats:sup>ions.</jats:p>

Synthesis, structural evolution and optical properties of a new family of oxychalcogenides [Sr3VO4][MQ3] (M = Ga, In, Q = S, Se)

“…† The bond lengths of Ga-S in [Sr 3 VO 4 ][GaS 3 ] are in the range of 2.214-2.349 Å, while the Ga-Se bond lengths in [Sr 3 VO 4 ][GaSe 3 ] are between 2.351-2.447 Å. Chalcogenides containing isolated [Ga 2 Q 6 ] 6− dimers are rarely reported with limited examples of K 6 Ga 2 Q 6 (Q = S, Se, Te) and Cs 6 Ga 2 Se 6 . [45][46][47][48] The heteroanionic composition provides more possibilities to form 0-D crystal structures containing isolated covalent clusters. [49][50][51][52] Once replacing the Ga 3+ with a larger In 3+ ion, the connection mode of the tetrahedra is changed, leading to the formation of a new structural type.…”