Thermal decomposition of some linear trinuclear schiff base complexes with acetate bridges

Ni(II)-M(II)-Ni(II) nuclear structured complexes were prepared from N,N'-bis(salicylidene)-1,3-propanediamine (LH2) and its derivatives N,N'-bis(salicylidene)-2,2'-dimethyl-1,3-propanediamine (LDMH2) and N,N'-bis(salicylidene)-2-hydroxy-1,3-propanediamine (LOH3), where M represents one of the following metal ions; Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II). Two different mu-bridges are found between the metal nucleus of the complexes. The phenolic oxygens and acetate ions tend to form mu-bridges between the terminal Ni(II) ions and central metal(II) ion. The coordinatively bonded DMF molecules, in the complexes, were observed to abandon the structure between 160-180 degrees C. Further heating resulted primarily in the thermal decomposition of the complexes above 310 degrees C, whereas metal oxide residue mixtures were observed above 650 degrees C.