Azido derivatives of dinuclear copper(II) and 1D polynuclear nickel(II) complexes containing an unsymmetrical bidentate amine: synthesis, crystalline architecture, and magnetic behavior

Dinuclear copper(II) complex [Cu 2 (L) 2 (μ 2-1,1 -N 3 ) 2 (N 3 ) 2 ] ( 1 ) with double μ 1,1 -azido bridges and polynuclear nickel(II) complex [Ni(L)(μ 2-1,1 -N 3 )(μ 2-1,3 -N 3 )] n ( 2 ) with alternate double μ 1,1 -azido and μ 1,3 -azido bridges [L = 1-amino-2-(dimethylamino)ethane, N 3 − = azide ion] have been synthesized and were characterized by physicochemical and spectroscopic methods. X-ray structural analysis revealed that each Cu(II) center of 1 adopts a distorted square-pyramidal geometry with a CuN 5 chromophore ligated through two N atoms of L, two N atoms of double bridging (μ 1,1 -N 3 ), and one N atom of terminal azide ion. On the other hand, each Ni(II) center around the asymmetric unit of 2 adopts a distorted octahedral geometry with a NiN 6 chromophore ligated through two N atoms of L, two N atoms of double μ 1,1 -N 3 , and two N atoms of double μ 1,3 -N 3 bridges. The adjacent nickel centers are connected to alternate double μ 1,1 -N 3 and double μ 1,3 -N 3 bridges, affording a one-dimensional (1D) polymeric chain structure. Temperature-dependent magnetic susceptibility measurements evidenced a dominant antiferromagnetic interaction between the metal centers of both complexes 1 and 2 .