Rare‐Earth Cadmium Tellurite Chlorides with a Structural Type Exhibiting [Ln 12 (TeO 3 ) 12 ] Slabs Alternating with CdCl 6 Octahedral Layers

A series of new rare‐earth cadmium metal tellurite chlorides were synthesized by the salt flux technique and characterized by single‐crystal X‐ray diffraction. The new compounds CdSm 2 (TeO 3 ) 2 Cl 4 ( I ), CdEu 2 (TeO 3 ) 2 Cl 4 ( II ), and CdGd 2 (TeO 3 ) 2 Cl 4 ( III ), adopt layered structures corresponding to sequences of metal oxide [LnTeO 3 ] and metal halide [Cd 1– x Cl 3 ] layers. They expand the known family of 2D rare‐earth selenium oxyhalides into the realm of tellurium(IV) compounds and add a new targeted structure type involving rock salt slabs formed by edge‐sharing CdCl 6 octahedra. The major differences in the structures of Se and Te compounds lie in the composition of the cationic slabs {[Ln 11 (SeO 3 ) 12 ] 9+ vs. [Ln 12 (TeO 3 ) 12 ] 12+ } and symmetry (orthorhombic for selenites vs. tetragonal for tellurites).