CuII complexes with the new Schiff base ligands as a mono- and bis-condensation products of 2-pyridinecarboxaldehyde-N-oxide with diethylenetriamine

Cu-II complexes with Schiff base ligands as a mono- (L-2) and bis- (L-1)-condensation products of 2-pyridincearboxaldehyde-N-oxide with diethylenetriamine with perchlorate and chloride counter anions were prepared. Two methods of preparation of Cu-II complex containing ligand L-2 are reported. Crystal structure of [CuL2(ClO4)(H2O)](ClO4) was solved. Chloride Cu-II complexes with ligand L-1 are formed in the ratio metal:ligand 1:1 and 2:1. The presence of the ligand L-1 in these complexes does not depend on the excess of Cu-II ions contrary to perchlorate complexes where the presence of the ligand L-1 or L-2 is dependent on the amount of Cu-II ions. By EPR measurements an exchange interactions were detected in CuL1(ClO4)(2).MeOH, CuL2(ClO4)(2).0.25EtOH and (Cu2LCl4)-Cl-1.2H(2)O. Amorphous character of all three complexes was detected by X-ray powder diffraction. (C) 2003 Elsevier Science B.V. All rights reserved.