Asymmetric bis-(μ_1,1-azido) bridged dinuclear copper(II) complex with N₂O donor Schiff base: Synthesis, structure and magnetic study

(Figure Presented) A double end-on azide-bridged centrosymmetric dinuclear copper(II) complex, [Cu₂(L)₂(N₃)₂], has been synthesized and characterized. X-ray crystal structure analysis has confirmed the structure; variable temperature (2-300 K) magnetic susceptibility measurement indicates antiferromagnetic exchange interactions with 2J = -0.45 cm^-1. A copper(II) complex, [Cu₂(L)₂(N₃)₂] [where HL = 2-((3-(methylamino)propylimino)methyl)-6-methoxyphenol] has been synthesized and characterized by elemental analysis, IR, UV-vis and fluorescence spectroscopy, and single-crystal X-ray diffraction studies. The complex crystallizes in the trigonal space group R3¯. The deprotonated tridentate Schiff base occupies three coordination sites of copper(II). The fourth coordination site is occupied by an azide. A symmetry-related azide from a different molecule coordinates with the fifth site of copper(II), thereby forming a double end-on azide-bridged centrosymmetric dimer. Variable temperature solid-state magnetic studies between 2 and 300 K were carried out and the data indicate predominant antiferromagnetic exchange interactions with 2J = -0.45 cm^-1. The magnetic field-dependent magnetization study (M - H) reveals existence of antiferromagnetic ordering at a lower temperature (2 K) with a very small coercive field (~20 Oe) suggesting soft magnet behavior of the complex.