Caesium bis(5‐bromosalicylaldehyde thiosemicarbazonato‐κ3O,N,S)ferrate(III): supramolecular arrangement of low‐spin FeIII complex anions mediated by Cs+ cations

The synthesis and crystal structure determination (at 293 K) of the title complex, Cs[Fe(C8H6BrN3OS)2], are reported. The compound is composed of two dianionic O,N,S‐tridentate 5‐bromosalicylaldehyde thiosemicarbazonate(2−) ligands coordinated to an FeIII cation, displaying a distorted octahedral geometry. The ligands are orientated in two perpendicular planes, with the O‐ and S‐donor atoms in cis positions and the N‐donor atoms in trans positions. The complex displays intermolecular N—H...O and N—H...Br hydrogen bonds, creating R44(18) rings, which link the FeIII units in the a and b directions. The FeIII cation is in the low‐spin state at 293 K.