Das erste Alkalimetall‐Lanthanoid(III)‐Iodid‐Oxotellurat(IV): Na2Lu3I3[TeO3]4

Abstract

AbstractColorless platelets of Na2Lu3I3[TeO3]4 were obtained within five days at 775 °C by the reaction of Lu2O3 and TeO2 in a 3:8 molar ratio with NaI added in excess as both fluxing agent and reactant in evacuated silica ampoules. It crystallizes in the monoclinic space group P2/c with the lattice parameters a = 921.69(5), b = 552.71(3), c = 1664.37(9) pm, β = 90.218(4)° and Z = 2. The crystal structure of Na2Lu3I3[TeO3]4 exhibits two crystallographically different Lu3+ cations, both coordinated by eight O2– anions as square antiprisms. These polyhedra are interconnected through four common edges to build up {}^2_∞{[LuO{}^e_8/2]5–} layers (e = edge‐linking) parallel to (100). Furthermore, the crystal structure includes a crystallographically unique Na+ cation surrounded by four O2– and four I– anions also in the shape of a square antiprism. These polyhedra connect via common (I2)–···(I2)– edges in generating {}^1_∞{[Na2O8I{}^e_4]18–} double‐strands that are further linked by (I1)– vertices to result in the formation of {}^2_∞{[Na2O8I3{}^e,v_3]17–} layers (v = vertex‐linking) spreading out parallel to (100) as well. Thus, the crystal structure contains two crystallographically distinct I– anions, of which (I1)– is coordinated nearly linear (∢ (Na–I1–Na) = 179.6°) by two Na+ cations, whereas (I2)– has contact to three of them displaying a distance of 114 pm from the triangular (Na+)3 plane. The crystal structure of Na2Lu3I3[TeO3]4 is completed by two crystallographically independent Te4+ cations that show stereochemically active non‐bonding electron pairs (“lone pairs”) and are located above and below the {}^2_∞{[LuO{}^e_8/2]5–} layers forming isolated ψ1‐tetrahedral [TeO3]2– anions (d(Te–O) = 188–190 pm) with all oxygen atoms.