To complete a previous characterization of complexes with a polycarboxylate ligand, imidazole-4,5-dicarboxylic acid (H(2)imdc), cobalt and zinc complexes with (Himdc)(-) ligand were synthesized. The precipitated Co(Himdc)(2)(H2O)(2) and Zn(Himdc)(2)(H2O)(2) complexes were characterized and their stability was studied by thermoanalytical techniques coupled to mass spectrometry, to prove their decomposition mechanism by evolved gas analysis (EGA-MS). The results confirmed that the decomposition mechanism, already proposed for the analog copper and nickel complexes, can be assumed as representative for these structures, independently from the central coordinating metal. (C) 2014 Elsevier B.V. All rights reserved.