Synthese und Kristallstruktur von (TeCl₃ ⁺)(MoOCl₄ ^–) / Synthesis and Crystal Structure of (TeCl₃ ⁺)(MoOCl₄ ^–)

Abstract

(TeCl 3 )(MoOCl 4 ) is obtained by the reaction of TeCl 4 and MoOCl 3 in a sealed ampoule at 180 °C. It forms yellow-green moisture sensitive crystals. The crystal structure determination (lattice constants a = 734.8(1), b = 1281.5(3), c = 1172.2(2) pm, β = 94.62(2)°, monoclinic space group P 2 1 /c, 2808 unique reflections for 92 parameters, final R = 0.029) shows that (TeCl 3 )(MoOCl 4 ) consists of square pyramidal (MoOCl 4 - ) anions and (TeCl 3 + ) cations. The (MoOCl 4 - ) anions are linked by asymmetric chlorine bridges and form centrosymmetric dimers (MoOCl 4 - ) 2 2- with the oxygen atoms located in the trans positions of the chlorine bridges. The coordination sphere for the Mo atom is a deformed octahedron of one oxygen and five chlorine atoms. Each trigonal pyramidal (TeCl 3 + ) cation is connected by chlorine bridges to two neighboured (MoOCl 4 ) 2 2- anions resulting in a strongly deformed octahedral environment of six chlorine atoms for the Te atom. The MoOCl 5 and TeCl 6 octahedra are linked by edges and corners and form layers parallel to the be plane. Alternatively the structure can be regarded as a close packing of Cl and O atoms with the layer sequence ABAC, A ··· and Mo and Te atoms located in one quater of the octahedral holes.