Synthesis, structure, and magnetic properties of a new binuclear Ni(II) complex supported by 1,4,8-triazacycloundecane

A new synthetic binuclear nickel(II) compound ([Ni2(tacud)2(μ-H2O)(μ-Cl)2]Cl2 (1); tacud = 1,4,8-triazacycloundecane) is reported. Compound 1 contains two Ni(II) ions bridged by two chloro and one aqua ligand resulting in a short Ni···Ni distance of 3.0187(10) Å. Each nickel is capped by terminal tacud ligands and possesses distorted octahedral geometry. This compound exhibits a new structural motif for metal complexes supported by tacud. Compound 1 exhibits two solvent dependent transitions in the UV–vis spectrum. Variable temperature SQUID magnetic susceptometry studies on 1 indicate mild ferromagnetism exists at room temperature (μeff = 4.78 μB) which increases upon temperature lowering. Magnetic analysis of 1 in the temperature range 2–300 K confirm weakly ferromagnetic behavior with J = +2.28 cm−1.

Graphical abstractA new binuclear nickel(II) complex, [Ni2(tacud)2(μ-H2O)(μ-Cl)2]Cl2 (tacud = 1,4,8-triazacycloundecane), is reported. In this complex, Ni(II) centers are bridged by two chloro and one aqua ligand while terminal positions are capped by tacud ligands. Magnetic studies reveal that the complex is weakly ferromagnetic.Figure optionsDownload full-size imageDownload as PowerPoint slide