A C2-symmetric antimonato polyoxovanadate cluster [V16Sb4O42(H2O)]8− derived from the {V18O42} archetype

Abstract

The new antimonato polyoxovanadate [V^IV₁₆Sb^III₄O₄₂(H₂O)]⁸⁻ cluster (1a) is the main structural motif of the solvothermally obtained compound {(trenH₂)Zn(tren)}₂[V₁₆Sb₄O₄₂(H₂O)]·xH₂O (x = 6–10) (1) (tren = tris(2-aminoethyl)amine). The C₂-symmetric cluster structure is closely related to the {V₁₈O₄₂} archetype. 1 crystallizes in the monoclinic space group C2/c with a = 30.7070(19) Å, b = 13.9512(5) Å, c = 23.1435(14) Å, β = 128.076(6)°, and V = 7804.8(7) ų. The orientation of the [Sb^III₂O₅]⁴⁻ groups in each cluster leads to intermolecular Sb⋯O contacts and the formation of channels between the clusters. [Zn(tren)(trenH₂)] complexes with trigonal bipyramidal coordination environments are located between the [V₁₆Sb₄O₄₂(H₂O)]⁸⁻ anions, and form a three dimensional network with them via strong N–H⋯O hydrogen bonds. Up to 250 °C crystal water molecules are emitted, which are reversibly incorporated in humid air.