The first triple phenoxido-bridged triangular NiIICuII2 complexes with a N2O2 donor di-Schiff base and pseudohalide (N(CN)2- or NCS-) ligands: Structural analyses and magnetic properties

Two triangular tri-nuclear, hetero-metallic copper(II)-nickel(II) complexes, [(CuL)(2)Ni(N(CN)(2))(2)]center dot H2O (I) and [(CuL)(2)Ni(NCS)(2)]center dot H2O (2) have been synthesized by reacting ligand complex [CuL] with Ni(ClO4)(2) in presence of polyatomic anions, dicyanamide (dca) or thiocyanate in methanol-water medium, where H2L is a N2O2 donor di-Schiff base derived from 1,3-propanediamine and 2-hydroxyacetophenone. Both the complexes have been structurally and magnetically characterized. In both complexes, two [CuL] units coordinate to a nickel atom through the coordination of the phenoxido oxygen atoms forming triple phenoxido bridges between each Cu(II) and Ni(II). A couple of terminal dca or N-bonded thiocyanate ions complete the distorted octahedral geometry around Ni(II) in 1 and 2 respectively. Variable temperature magnetic susceptibility measurements show the presence of moderate antiferromagnetic exchange interactions mediated through the phenoxido bridges with J values (H = -J Sigma SiSi+1) of -49 and -42 cm(-1) for 1 and 2 respectively. (C) 2013 Elsevier Ltd. All rights reserved.