A Structural Comparison of Two Thallium Copper Erbium Sulfides: TlCu3Er2S5 and Tl2Cu5Er3S8

作者：Eberle Marcel A; Babo Jean Marie; Schleid Thomas^*

来源：Zeitschrift Fur Naturforschung Section B-a Journal of Chemical Sciences, 2014, 69(8): 851-858.

DOI：10.5560/ZNB.2014-4074

• Thallium
• Copper
• Erbium
• Sulfides
• Solid-State Crystal Structures

Orange TlCu3Er2S5 crystallizes in the orthorhombic space group Cmcm (a = 391.27(2), b = 1382.91(7), c = 1630.54(8) pm, Z = 4). Its crystal structure contains one Tl+, one Er3+, two Cu+, and three S2- ions as crystallographically unique components. All Cu+ cations are coordinated by four S2- anions to form [CuS4](7-) tetrahedra, which have vertex- and edge-connectivity to build up (2)(infinity){[Cu3S5](7-)} layers parallel to the (010) plane. The Er3+ cations are octahedrally surrounded by six S2- anions. These [ErS6](9-) units share trans-oriented edges forming linear chains, which are further linked by common vertices yielding. (1)(infinity) {[Er2S5](4-) double strands. Further fusion via common vertices results in (2)(infinity){[Er2S5](4-)} layers parallel to the (010) plane. Alternatingly stacked along [010] and condensed via S2- anions, these two types of layers form a three-dimensional framework, leaving tunnels along [100], where the Tl+ cations fit in. These are each coordinated by eight S2- anions in the shape of bicapped trigonal prisms. Tl2Cu5Er3S8 was obtained as black single crystals with metallic luster (monoclinic, Cm, a = 1381.69(7), b = 390.73(2), c = 1435.98(7) pm, beta = 111.132(3)degrees, Z = 2). Four of the five crystallographically different Cu+ cations are tetrahedrally surrounded by S2- anions, whereas (Cu3)(+) is situated in sulfur triangles. Connected via common vertices and edges, the copper-sulfur polyhedra form strongly corrugated (2)(infinity)[Cu5S8](11-) layers parallel to the (20 (1) over bar) plane. All Er3+ cations are again coordinated by six S2- anions in the shape of [ErS6](9-) octahedra. Their condensation via edges and vertices leads to (2)(infinity){[Er3S8](7-)} layers spreading out parallel to the (010) plane. Both types of anionic layers result in a three-dimensional framework through sulfide fusion, which leaves tunnels running along [010] occupied by Tl+ cations. The two crystallographically different Tl+ cations both have eight coordinating S2- anions forming bicapped trigonal prisms. Remarkably enough, the ion closest to (Tl1)(+) is not a S2- anion (shortest Tl+ -S2- bond: 305 pm), but a (Cu3)(+) cation at a distance of just 291 pm.

• 出版日期2014-8