Structural correlations in nickel(II)–thiodiacetato complexes: molecular and crystal structures and properties of [Ni(tda)(H2O)3]

Triaqua(thiodiacetato)nickel(II) has been synthesized and studied by X-ray crystallography, thermal, spectral and magnetic methods. The compound crystallizes in the triclinic system, space group image, in contrast to the related compound [Ni(tda)(H2O)3] · H2O (orthorhombic) reported long time ago. As in other four Ni–tda derivatives, the metal atom exhibits an octahedral coordination and tda ligand adopts a fac-tridentate chelating role. The studied compound is closely related to [Zn(tda)(H2O)3]. In addition, a structural comparison of the binary and ternary Ni–tda derivatives reveals that auxiliary N-donor ligands bind the metal atom using the trans-positions towards the Ni–O(carboxylato) bonds, but not in trans to the Ni–S(thioether) bond.