Notizen: Darstellung und Kristallstruktur von Cs₄Sn₂Se₆ / Preparation and Crystal Structure of Cs₄Sn₂Se₆

Abstract

The selenostannate(IV) Cs4Sn2Se6 has been prepared by methanolothermal reaction of Cs2CO3 with SnSe2 at 160°C and 13 bar. The [Sn2Se6]4— anions contain two edge-bridged SnSe4 tetrahedra and display crystallographic C2h symmetry. The bridging Sn—Se distances of 2.587(1) are markedly longer than the terminal Sn—Se distances of 2.447(1) and 2.452(2) Å.

Synthesis and Structure of [Sn4Se11]6-,1∞ [Sn2Se52-], and1∞ [Sn3Se72-] - Model Anions for the Solventothermal Reaction Pathway to Lamellar Selenidostannates(IV)

“…2) and 2 can be regarded as being composed of two corner-bridged [Sn 2 Se 6 ] 4± ditetrahedra, whose four-membered (SnSe) 2 rings are positioned effectively at right angles to one another (dihedral angle = 85.8°in 1). These [Sn 2 Se 6 ] 4± building blocks represent the predominant tin-containing species in mildly alkaline solution and have been structurally characterized in alkali metal salts of the type A 4 Sn 2 Se 6 with A = Na´13 H 2 O [19], K [20], Rb [21] and Cs [22]. In accordance with the metrical data for isolated [Sn 2 Se 6 ] 4± anions, the terminal more polar Sn1±Se1 and Sn1±Se2 bonds (2.461(2), 2.464(2) A Ê ) in 1 are markedly shorter than those between Sn1 and the bridging selenium atoms Se3 and Se4 (2.611(2), 2.606(2) A Ê ).…”

Crystal structure of the Ag2SiS3 compound

“…4a) (SG P1) [15], Cs 2 SnSe 3 (SG C2/m) (Fig. 4b) [16], KAuSnS 3 (SG P4/mcc) [17], and K 2 Y 4 Sn 2 S 11 (SG P4/ncc) [18]. One should note that all the listed crystal structures are centrosymmetrical which is likely related to the low polarization ability of the anionic units [Si(Ge,Sn) 2 S(Se) 6 ]; the single-charged cations possess octahedral coordination surrounding in these structures.…”

Solventothermal Synthesis and Structure of Lamellar Alkali Metal Selenidostannates(IV) A4Sn4Se10·xH2O with 20- (A=Cs; x=3.2) and 36-Membered Pores (A=K, Rb; x=4.5, 1.5)

“…3d). [Sn Se ]\ anions (12) can be isolated together with 3 at the higher starting pH value associated with the reduced solvent volume.…”

“…After tempering for 24 h at this temperature, the glass tube was cooled to 203C at 13C ) h\ to a!ord bunches of darkred needles of 3 (yield"38%, based on Se) that were separated manually from yellow plates of Cs Sn Se (yield" 35%) (12).…”