Three nickel(II) complexes derived from a tridentate NNO donor Schiff base ligand: Syntheses, crystal structures and magnetic properties
摘要:
Three new Ni(II) complexes, [NiL(NO2)(H2O)] (1), [Ni2L2(PhCH2COO)(2)(H2O)] (2) and [Ni2L2(N(CN)(2))(2)(H2O)] (3), have been synthesized using a tridentate Schiff base ligand, 1-[(3-dimethylamino-propylimino)-methyl]-naphthalen-2-ol (HL) and the polyatomic monoanions NO2-, PhCH2COO- or N(CN)(2)(-). All three complexes (1-3) have been characterized by spectral analysis and X-ray crystallography. Structural analyses reveal that complex 1 is mononuclear, in which the Ni(II) ion is in a distorted octahedral environment, coordinated by the deprotonated tridentate Schiff base (L), a chelating nitrite and one water molecule. The structures of both 2 and 3 consist of dinuclear octahedral Ni(II) units with crystallographic C-2 symmetry. In complex 2, two mu(2)-phenoxido and a water molecule bridge the two Ni(II) centers to make the complex a face sharing bioctahedron, whereas in 3 the Ni(II) atoms are bridged by two mu(1,5)-dicyanamide ligands. Variable temperature magnetic susceptibility measurements show the presence of ferromagnetic coupling in complex 2 with J = +26.20 cm(-1) and antiferromagnetic coupling in complex 3 with J = -1.90 cm(-1). (C) 2013 Elsevier Ltd. All rights reserved.