Spectrophotometric Study of New Schiff Base Complexes with Some Metal Ions in Methanol Solution

The complexation reactions between N,N'-3,6-dioxa-1,8-octanebis (salicylaldimine) [saldioxen(I)] and Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) were studied spectrophotometrically in methanol solution at 25 °C. The stoichiometry of the complexes were obtained as 2:1 and 1:1 sadioxen-metal ion using mole ratio method. The formation constants of the complexes were determined, and found to follow the Irving-Williams, rule for the cations of the first transition series. IR spectroscopy and other evidence indicated that, in 2:1 complexes, the coordination takes place through the azomethin nitrogen atoms only, whereas in 1:1 complexes, metal ion coordinated with ligand through two azomethin groups and the phenolic oxygen atoms.