SYNTHESIS AND CHARACTERIZATION OF BINUCLEAR CU(II), NI(II) AND CO(II)CHELATES WITH TETRADENTATE SCHIFF-BASE LIGANDS DERIVED FROM 1,5-DIAMINONAPHTHALENE

A new series of copper(II), nickel(II) and cobalt(II) chelates contain ing the binucleating tetradentate Schiff base ligands N,N'-bis(salicyl idene)-1,5-diaminonaphthalene (H(2)L), -bis(3-methoxysalicylidene)-1,5 -diaminonaphthalene (H(2)L') and -bis(4-hydroxysalicylidene)-1,5-diami nonaphthalene (H(2)L '') have been synthesized. These compounds have b een characterized by elemental analyses, conductivity measurements, ma gnetic susceptibility, thermoanalyses (TG-DTA), infrared and electroni c spectral data. The results suggest that the Schiff bases function as tetradentate ligands coordinating through the ONNO donor system and i ndicate a binuclear structure for the Cu(II) complexes with pseudo-tet rahedral geometry and binuclear structures for the Co(II) and Ni(II) c omplexes with pseudo-octahedral geometry. All complexes are non-electr olytes.