Synthesis and Structure Determination of Ag₅HgSbO₆, Comparison with AgHg₃SbO₆ and Ag₅Pb₂O₆

Abstract

From solid state reactions of Ag2O, HgO, and Sb2O3 at high temperatures under elevated oxygen pressures a new silver mercury antimonate, Ag5HgSbO6, has been obtained. According to a single crystal structure determination Ag5HgSbO6 crystallizes in space group P$\bar{3}$1c (no. 163) with a = 5.9263(4), c = 12.3023(7) Å, V = 374.18(4) Å3, Z = 2, 498 independent reflections, R1 = 0.030, wR2 = 0.059 (I ≥ 2 σ (I). Ag5HgSbO6 consists of HgSbO6 layers, analogous to BiI3, which are separated by Kagome nets formed by Ag+ ions. Perpendicular to these layers and along the c axis linear strings of Ag+ ions run through the large voids of the layers. Accordingly, Ag5HgSbO6 adopts the Ag5Pb2O6 type of structure where the lead positions are occupied by mercury and antimony alternatingly. The finding of mercury in octahedral coordination, particularly besides the lower charged Ag+ cations in linear coordination, which is also highly preferred by Hg2+ ions, is rather unexpected. Ag5HgSbO6 starts to decompose at 450 °C and, in contrast to subvalent and metallic Ag5Pb2O6, the new compound is charge balanced and semiconducting (ρ = 5.7 Ωcm at ambient temperature, Ea = 0.047 eV).

Ag1+xTlO2 (0.03 ≤ x ≤ 0.18), Novel Adaptations of the Delafossite Structure Type Featuring Subvalent Silver

“…The group 11 elements, Cu and Ag, always adopt a linear coordination. Within the resulting 3 R and 2 H delafossites the O– A + –O dumbbells are oriented parallel to the c axis, while they are inclined to the c axis direction in the related Ag 5 Pb 2 O 6 structure family 37,38. In the new silver thallates these building units (see Figure 1) are combined to form different stacking variants, see Figure 2.…”

Rb9–xAg3+xSc2(WO4)9: a new glaserite-related structure type, rubidium disorder, ionic conductivity

“…, Ag 2 Cu 2 O 3 (Gó mez-Romero et al, 1999), Ag 4 SiO 4(Klein & Jansen, 2008), Ag 5 HgSbO 6(Klein & Jansen, 2012) and [Ag 2 M(Te 2 O 5 ) 2 ]SO 4 (M = Ce, Th) (Poe et al, 2018). The Rb1 and Rb2 atoms are in ninefold environments with the coordination polyhedra as a distorted tricapped trigonal prism [Fig.…”