Molecular building blocks for solid‐state chalcogenides: solvothermal synthesis of [Mn(en)3]Te4 and [Fe(en)3]2(Sb2Se5)

Two new molecular metal chalcogenides, tris­(ethyl­enedi­amine‐N,N′)­manganese(II) tetratelluride, Mn(C₂H₈N₂)₃]Te₄, (I), and bis­tris­(ethyl­enedi­amine‐N,N′)­iron(II)] penta­seleno­diantimonate(III), Fe(C₂H₈N₂)₃]₂(Sb₂Se₅), (II), containing the isolated molecular building blocks Te₄^2? and Sb₂Se₅^4?, have been synthesized by solvothermal reactions in an ethyl­enedi­amine solution at 433 K. The anion Te₄^2? in (I) is a zigzag oligometric chain with Te—Te bond lengths in the range 2.709–2.751 Å. There is a very short contact 3.329 (1) Å] between a pair of neighboring Te₄^2? anions. In (II), each Sb atom is surrounded by three Se atoms to give a tripodal coordination. One of the three independent Se atoms is a μ₂‐bridging ligand between two Sb atoms; the other two are terminal.