A synthetic approach towards homotrinuclear complexes: Design of Mn(II), Ni(II) and Cu(II) trinuclear complexes using two new unsymmetrical tetradentate ligands derived from 3-formylsalicylic acid

摘要

Two new polydentate ligands able to generate homotrinuclear complexes have been synthesized: 3-(N-(2-pyridylmethyl)formimidoyl)salicylic acid (H(2)fsaamp), 1, and 3-(N-(N',N'-dimethylaminoethyl)formimidoyl)salicylic acid, H(2)fsadme, 2. The synthetic process is as follows: the reaction of 3-formylsalicylic acid, H(2)fsa, with 2-(aminomethyl)pyridine and (N,N-dimethyl)ethylenediamine, respectively, leads to the Schiff bases H(2)fsaamp and H(2)fsadme. The two ligands have been characterized by chemical analyses, IR and H-1 NMR spectroscopy. The reaction of these ligands with Mn(II), Cu(II) and Ni(II) perchlorates yields trinuclear complexes: Ni-3(fsaamp)(2)(H2O)(4)(ClO4)(2) (3), Cu-3(fsaamp)(2)(H2O)(2)(ClO4)(2) (4), Mn-3(fsadme)(2)(H2O)(4)(ClO4)(2) (5) and Cu-3(fsadme)(2)(ClO4)(2) (6), which have been characterized by means of chemical analyses and spectroscopic methods. The magnetic data are in agreement with the presence of three paramagnetic centers within the homotrinuclear species. [References: 16]