A SYNTHETIC APPROACH TOWARDS HOMOTRINUCLEAR COMPLEXES - DESIGN OF MN(II), NI(II) AND CU(II) TRINUCLEAR COMPLEXES USING 2 NEW UNSYMMETRICAL TETRADENTATE LIGANDS DERIVED FROM 3-FORMYLSALICYLIC ACID

Two new polydentate ligands able to generate homotrinuclear complexes have been synthesized: 3-(N-(2-pyridylmethyl)formimidoyl)salicylic aci d (H(2)fsaamp), 1, and (N-(N',N'-dimethylaminoethyl)formimidoyl)salicy lic acid, H(2)fsadme, 2. The synthetic process is as follows: the reac tion of 3-formylsalicylic acid, H(2)fsa, with 2-(aminomethyl)pyridine and (N,N-dimethyl)ethylenediamine, respectively, leads to the Schiff b ases H(2)fsaamp and H(2)fsadme. The two ligands have been characterize d by chemical analyses, IR and H-1 NMR spectroscopy. The reaction of t hese ligands with Mn(II), Cu(II) and Ni(II) perchlorates yields trinuc lear 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(fs adme)(2)(ClO4)(2) (6), which have been characterized by means of chemi cal analyses and spectroscopic methods. The magnetic data are in agree ment with the presence of three paramagnetic centers within the homotr inuclear species.