Synthesis, crystal structures and magnetic properties of five new metal(II) compounds constructed with isomers of aminobenzonitrile and dicyanamide ligands

Abstract

Five new compounds formulated as [Ni II(dca) 2( para-ABN) 2(H 2O) 2] ( 1), [Cu II(dca) 2( para-ABN) 2(H 2O) 2] ( 2), [Cu II(dca) 2( para-ABN) 2] n , ( 3), [Cu II(dca) 2( ortho-ABN) 2] n , ( 4) and [Cd II(dca) 2( meta-ABN) 2] n ( 5), where dca = dicyanamide and ABN = aminobenzonitrile, have been synthesized and characterized by single crystal X-ray diffraction studies and low temperature (300–2 K) magnetic measurements. The structural analyses revealed that 1 and 2 are isomorphous where dca and para-ABN both act as monodentate ligands. 3 consists of infinite double stranded chains of Cu(II) ions connected through the para-ABN bridges whereas 4 and 5 consist of infinite double stranded chains of Cu(II) and Cd(II) respectively, connected through μ 1,5-dca bridges. The compounds extend their geometries to three-dimensional for 1– 3 and 5 and two-dimensional for 4 through hydrogen bonding interactions. All the metal ions Ni 2+, Cu 2+ and Cd 2+ are located on inversion centres and have distorted octahedral coordination geometries. The variable temperature magnetic susceptibility measurements show that the global feature of the χ M T versus T curves for 3 and 4 is characteristic of very weak antiferromagnetic interactions and between 300 and 2 K the best fit parameters were determined as J = −2.35 and −5.1 cm −1, respectively.