A rare ferromagnetically coupled asymmetric doubly azido bridged copper(II) dimer with an N, N, O donor Schiff base

A new end-to-end (EE) doubly azido bridged dinuclear complex [Cu2L2(μ1,3-N3)2] (1) [where L = (E)-4-(2-(dimethylamino)ethylimino)-1,1,1-trifluoropentan-2-one)] has been synthesized and characterized by elemental and spectroscopic techniques. Single crystal X-ray diffraction analysis reveals that the dimeric complex possesses a center of inversion. Each copper atom in 1 is in a distorted square pyramidal geometry with a CuN4O chromophore as revealed from the τ value, 0.19. The four basal positions are occupied by two imine N and one keto O atom of the Schiff base and one N atom from the azide anion. Another N atom from a coordinated azide occupies the apical position. Temperature dependent magnetic susceptibility of 1 was fitted using the Bleaney–Bowers expression which led to the parameters J = 13.6 cm−1 and R = 3.4 × 10−5. It indicates a ferromagnetic interaction through the double azido bridges connecting the individual copper Schiff base units.

Graphical abstractA new end-to-end (EE) doubly azido bridged centrosymmetric dinuclear complex has been synthesized and characterized with elemental and spectroscopic techniques. In the complex, each copper atom is in a distorted square pyramidal geometry with a CuN4O chromophore. Temperature dependent magnetic susceptibility, fitted using the Bleaney–Bowers expression indicates a ferromagnetic interaction through the double azido bridges connecting the adjacent copper(II) centers.Figure optionsDownload full-size imageDownload as PowerPoint slide