The cation and anion bonding modes make a difference: an unprecedented layered structure and a tri(hetero)nuclear moiety in thioantimonates(V).

Mixing solutions of M2+ (M = Cu2+ or Zn2+) salts containing cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane) as the ligand and an aqueous solution of Na3SbS4·9H2O at room temperature led to the crystallization of two new compounds within minutes: {[Cu(cyclam)]3[SbS4]2}n·20nH2O (I) and {[Zn(cyclam)]3[SbS4]2}·8H2O (II). In the structure of I [SbS4]3- anions acting as a tridentate ligand join CuN4S2 octahedra generating twelve-membered rings by corner-sharing of SbS4 and CuN4S2 units. The rings are condensed into layers, which are stacked onto each other in a 6R polytype manner. The layers contain large pores with the water molecules located between the layers above and below the pores. In contrast, the structure of II comprises a discrete molecular tri(hetero)nuclear moiety with a bidentate [SbS4]3- anion connecting two rectangular pyramidal ZnN4S polyhedra. The crystal water molecules of I and II can be thermally removed, and I and II are recovered by treatment under a humid atmosphere. The EPR spectrum of I indicates the presence of Cu2+ cations, which is unusual in the environment of S2- anions. The different bonding situations and the preferences for the coordination geometries of Cu2+ and Zn2+ cations are rationalized by DFT based calculations, demonstrating that Cu2+ prefers an octahedral environment while Zn2+ adopts the square-pyramidal coordination. The pronounced differences in the vibrational spectra are also analyzed with DFT, showing how the different modes are influenced by the differing bond strengths.