Synthesis, structures and characterization of the dinuclear nickel(II) complexes containing N, N, N′, N′-tetrakis[(1-ethyl-2-benzimidazolyl)methyl]-2-hydroxy-1,3-diaminopropane and an azide ion

Abstract

Two dinuclear nickel(II) complexes, [Ni 2(L-Et)(N 3)(H 2O) 3](NO 3) 2 · 2H 2O ( 1) and [Ni 2(L-Et)(μ-1,3-N 3)(H 2O) 2](NO 3) 2 · 4H 2O ( 2) containing (HL-Et = N, N, N′, N′-tetrakis[(1-ethyl-2-benzimidazolyl)methyl]-2-hydroxy-1,3-diaminopropane), have been synthesized and characterized by their IR and UV–Vis spectra and magnetic susceptibilities. The crystal structures of [Ni 2(L-Et)(N 3)(H 2O) 3](NO 3) 2 · CH 3OH ( 1′) and [Ni 2(L-Et)(μ-1,3-N 3)(H 2O) 2](NO 3) 2 · 2C 2H 5OH ( 2′) similar to 1 and 2 were determined by X-ray crystallography. In 1′, the two nickel(II) ions are bridged by only an alkoxo group of L-Et −, while an azido and an alkoxo connect two nickel(II) ions in 2′. Magnetic susceptibility measurements (2–300 K) showed a weak ferromagnetic exchange coupling between the two nickel(II) ions (2 J = 10.1 cm −1) for 1. On the other hand, antiferromagnetic interactions were observed for 2 (2 J = −15.8 cm −1).