Hexatellurium Rings in Coordination Polymers and Molecular Clusters: Synthesis and Crystal Structures of [<i>M</i>(Te₆)]<i>X</i>₃ (<i>M</i> = Rh, Ir; <i>X</i> = Cl, Br, I) and [Ru₂(Te₆)](TeBr₃)₄(TeBr₂)₂

Abstract

Abstract The reaction of an electron‐rich transition metal M ( M = Ru, Rh, Ir), tellurium and Te X 4 ( X = Cl, Br, I) resulted in black crystals of five ternary coordination polymers with the general composition [ M III (Te 6 )] X 3 ( M = Rh, Ir) and of the molecular cluster compound [Ru II 2 (Te 6 )](Te II Br 3 ) 4 (Te II Br 2 ) 2 . X‐ray diffraction on single‐crystals revealed that the compounds [ M (Te 6 )] X 3 crystallize isostructurally in the trigonal space group type R $\bar{3}$ c . In their crystal structures linear, positively charged [ M III (Te 6 )] chains form the motif of a hexagonal rod packing. In the chain, each of the formally uncharged Te 6 molecules with chair conformation acts as a bis‐tridentate bridging ligand to two M atoms. The octahedrally coordinated M atoms are spiro atoms in the chain of trans vertices sharing heterocubane fragments. Including the isolated halide ions, which provide charge balance, the entire arrangement resembles a cut‐out of the α‐polonium structure type.In the monoclinic compound Ru 2 Te 12 Br 16 (space group P 2 1 / n ), the ruthenium atoms of the hetero‐cubane core of the molecular cluster [Ru 2 (Te 6 )](TeBr 3 ) 4 (TeBr 2 ) 2 are saturated by terminal bromidotellurate(II) groups. Again, the Te 6 ring is formally uncharged. With the tellurium atoms acting as electron‐pair donors the 18 electron rule is fulfilled for the M atoms in all compounds.