Polychelates derived from 4,4′-(4,4′-biphenylylenebisazo)di(salicylaldehyde oxime)

Polychelates of Ni(II), Co(II), Cu(II), Zn(II), and Mn(II) were synthesized from bis 4,4′-(4,4′-biphenylenebisazo)di(salicylaldehyde oxime) and metal chlorides. All the chelates are dark in colour and insoluble in common organic solvents. Their most probable structures were determined by visible reflectance spectroscopy and magnetic measurements in conjunction with thermogravimetric and IR measurements. Elemental analyses indicate a ligand: metal ratio of 1:1 and the association of water molecules with the central metal. The decomposition temperatures of the polychelates decrease in the following order: Zn(II) > Co(II) > Ni(II) > Mn(II) > Cu(II).