Synthesis and characterization of oxazolone complexes with Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) in different counterions

Oxazolone forms (1:1) complexes with Fe2+, Co2+, Ni2+, Cu2+ and Zn2+ chlorides, as well as forms (1:1) complexes with Co2+ and Cu2+ acetates. All the complexes are found to be non-electrolytes in DMF; tetrahedral, square-planar and octahedral structures are assigned to them based on electronic and magnetic data. IR studies reveal that the complexes are formed by donating the lone-pair electron from O and N atoms to the metal ion. The thermal decomposition of the {[}ML(.)mX(.)nH(2)O](y)(H2O)-H-. chelates was studied by TG-DTA techniques. The mechanism of the decomposition has been established from TG-DTA data. The kinetic parameters, activation energy (E-a) and pre-exponential factor (A), were calculated from TG curves using Coats and Redfern method. Relative thermal stabilities of the chelates have been evaluated on the basis of these parameters. (C) 2003 Published by Elsevier Science B.V.