The First Structural Characterization of a \(\mathbf{Ni(NCS)}_{\mathbf{6}}^{\mathbf{4}-}\) Bridged Homometallic Ni(II) Chain Derived from an N₃O Donor Schiff Base Ligand

Thiocyanate bridged homometallic Ni(II) chains have potential applications in areas such as molecular magnetism and spintronics due to their tunable magnetic properties. The magnetic properties of these chains are of particular interest and can lead to intriguing magnetic behaviors, such as antiferromagnetic or ferromagnetic interactions. In this context, we have successfully synthesized a \(\text{Ni(NCS)}_{\text{6}}^{\text{4}-}\) bridge Ni(II) chain complex [Ni₂(H₂L)₂(μ1,3-NCS)₂(NCS)₄]_n∙2nCH₃CN (1), derived from a tetradentate N₃O donor Schiff base ligand (HL). It has been thoroughly characterized by the help of elemental analysis and IR spectroscopy. Single crystal X-ray crystallography has confirmed the geometry of the chain complexes. Both Ni1 and Ni2 centers exhibit hexa-coordination with slightly distorted octahedral geometries, and their coordination environments differ significantly (NiN₂O₂S₂ for Ni1 and NiN₆ for Ni2). Within the solid-state structure of the complex, a noteworthy two-dimensional network of hydrogen bonding is observed. The present complex showing a unique example in the realm of single thiocyanato-bridged Ni(II) chains.