Unprecedented Connection Mode of [V16Sb4O42(H2O)]8- Cluster Anions by Mn2+ Centered Complexes: Solvothermal Synthesis and Properties of {[Mn(teta)]4V16Sb4O42(H2O} n·[(H2O)12] n

The new compound {[Mn(teta)]₄V₁₆Sb₄O₄₂} _n ·[(H₂O)₁₂] _n ( 1) was synthesized under solvothermal conditions. The crystal structure features the high nuclearity [V₁₆^IVSb₄^IIIO₄₂(H₂O)]^8- cluster anion, which consists of two rings composed of 8 edge-sharing VO₅ polyhedra. The rings are perpendicular to each other generating four niches, which are occupied by two VO₅ pyramids and two handle-like Sb₂O₅ units. The two unique anions are each surrounded by eight Mn²⁺ centered complexes via Mn-O_term-V bonds. Such an expansion has never been observed in heterometal polyoxovanadate chemistry. The connection mode between cluster anions and complex cations generates two individual layers stacked onto each other. Between the layers weak Sb ···O contacts are observed. The crystal water molecules are mainly located in the empty space between the layers. Upon heating H₂O molecules are removed, while the crystal structure remains intact. The magnetic behavior is dominated by strong antiferromagnetic exchange interactions between the central V⁴⁺ ions, while the interaction between the cluster anion and central Mn²⁺ ions is significantly less pronounced. [ABSTRACT FROM AUTHOR]