Two further members of the triclinic lanthanoid(III) chloride oxoarsenate(III) series <i>Ln</i> ₃Cl₂[AsO₃][As₂O₅] with <i>Ln</i> = Eu and Gd

Abstract Eu 3 Cl 2 [AsO 3 ][As 2 O 5 ] ( a = 541.45(4) pm, b = 837.46(6) pm, c = 1107.56(8) pm, α = 90.059(2)°, β = 94.628(2)°, γ = 90.449(2)°) and Gd 3 Cl 2 [AsO 3 ][As 2 O 5 ] ( a = 539.89(4) pm, b = 838.20(6) pm, c = 1103.10(8) pm, α = 90.056(2)°, β = 94.601(2)°, γ = 90.388(2)°) crystallize isotypically with Sm 3 Cl 2 [AsO 3 ][As 2 O 5 ] in the triclinic space group P <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <m:mrow> <m:mover accent="true"> <m:mn>1</m:mn> <m:mo>‾</m:mo> </m:mover> </m:mrow> </m:math> $\bar{1}$ with Z = 2. Colorless, transparent, platelet-shaped single crystals of Eu 3 Cl 2 [AsO 3 ][As 2 O 5 ] and Gd 3 Cl 2 [AsO 3 ][As 2 O 5 ] were obtained by solid-state syntheses from their binary components in fused silica ampoules at temperatures around 800 °C.