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A series of aliphatic amide complexes of nickel(II), cobalt(II) and copper(II) chlorides has been prepared. These complexes have the general formulae: NiL 2 Cl 2 ·2H 2 O, NiL 2 Cl 2 , Ni 3 L 2 Cl 6 , Ni 3 LCl 6 , CoL 2 Cl 2 and CuL 2 Cl 2 , where L is the amide ligand. Ligands ranging from formamide to butyramide, both with and without N -methyl and N -ethyl substituents, were used. The complexes were found, from the absorption spectra, to be octahedral or distorted-octahedral, except for some of the cobalt complexes with dimethyl substituted ligands which are tetrahedral. Infrared spectra confirm that coordination to the metal ion is through the carbonyl oxygen. The effects of the structure and the nature of the different amide ligands on the thermal stabilities of the complexes have been investigated by thermal analysis. As indicators of the stability of the metal–amide binding, thermal decomposition onset temperatures ( T e ), peak temperatures ( T max ) and enthalpies (Δ H L ) were compared for complexes with similar composition, geometrical structure and decomposition stoichiometry. Results do not support the enhancement of thermal quantities with increasing basicity of the amides. Instead, steric factors appear to play a more important role in determining the magnitudes of Δ H L , T e and T max |
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