Two new end-to-end single dicyanamide bridged Cu(II) complexes with Schiff base ligands: Structural, electrochemical and magnetic properties

Abstract The synthesis, crystal structures and magnetic properties of two different copper(II) complexes of formula [Cu(L 1 )(dca)] n  ·  n ClO 4 ( 1 ) and [Cu(L 2 )] 2 (dca)(ClO 4 ) ( 2 ) [L 1  =  N , N -dimethylethylene- N ′-(pyridine-2-carbaldiiminato), HL 2  =  N , N -dimethylethylene- N ′-salicylaldiiminato, dca = dicyanamide anion] are described. Spectroscopic and electrochemical properties have also been discussed. A one-dimensional chain structure with single, symmetrical, μ 1,5 -dca bridges is found in compound 1 . The copper atom in 1 has a square pyramidal geometry. A tridentate Schiff base ligand, having NNN donor sites, and one nitrogen atom from dca occupy the basal plane. N(18) of a neighbouring unit occupies the apical site. The Schiff base used in compound 2 is a tridentate anion with NNO donor sites, which changes the structure in a dinuclear unit of copper atoms bridged by single end-to-end dicyanamide ion. The environment around copper in 2 is square planar. Magnetic susceptibility measurements for 1 and 2 reveal the occurrence of weak antiferromagnetic interaction through the dca ligand.