Thermal behavior study of palladium(II) complexes containing the iminic ligand N,N′-bis(3,4-dimethoxybenzaldehyde) ethane-1,2-diamine

this study describes the synthesis, characterization and thermal behavior study of the schiff base n,n′-bis(3,4-dimethoxybenzaldehyde)ethane-1,2-diamine (c.1) and four new compounds of palladium(ii) n,n-chelate coordination, with the general formula [pd(x1)(x2)(3,4dm-1,2am)] where 3,4dm-1,2am=n,n′-bis(3,4-dimethoxybenzaldehyde)ethane-1,2-diamine, x1 = x2 = cl− (c.2), x1 = x2 = cl− and br− (c.3), x1 = x2 = n3− (c.4) and x1 = x2 = nco− (c.5). the compounds were characterized by elemental analysis, infrared vibrational spectroscopy (ir) and nuclear magnetic resonance (nmr) 1h and 13c. the tg/dta curves showed that the thermal decomposition of the c2–c.5 complexes occurred in steps that involve the removal of both inorganic and organic ligand, and palladium oxidation steps forming palladium(ii) oxide followed by the reduction of pdo into pd(0), this being the constituent of the residual mass observed at the end of the tg curves, which have values consistent with the expected ones. the formed compounds can be ordered according to thermal stability considering the initial decomposition temperature (c.5 > c.2 > c.3 > c.4).