Synthesis and characterization of some new Co(II) and Cd(II) macroacyclic Schiff-base complexes containing piperazine moiety

Three Cd(II) or Co(II) macroacyclic Schiff base complexes [(CoLBr)-Br-1]ClO4 (1), [(CdLCl)-Cl-2]ClO4 (2) and [CdL3(NO3)]ClO4 (3) were prepared by template condensation of 2-pyridinecarboxaldehyde and three different amines containing piperazine moiety, N,N'-bis(2-aminoethyl)piperazine, N,N'(2-aminoethyl)(3-aminopropyl)piperazine and N,N'-bis(3-aminopropyl)piperazine, in the presence of Co(II) or Cd(II) metal ions, respectively. All complexes have been studied with IR, FAB mass and microanalysis and for complex (3) by H-1 and C-13 NMR spectra. One of these complexes, [CdL3(NO3)]ClO4 (3) has been characterized through X-ray crystallography. In complex (3), the CA(II) ion is coordinated by the six nitrogen donor atoms from the ligand and by one oxygen atom from a monodentate nitrate ion in a N6O environment. (C) 2009 Elsevier Ltd. All rights reserved.