Study of [2-(2’-pyridyl)imidazole] complexes to confirm two main characteristic thermoanalytical behaviors of transition metal complexes based on imidazole derivatives

Imidazole derivative ligands are recognized as useful models for biomimetic complexes. Amongthe inorganic–organic hybrid complexes, those with derivatives of imidazole heterocyclic N-donorligands are interesting for their framework. In previous studies of complexes with imidazolederivative ligands, our group reported two main thermally induced decomposition behaviorssupporting two different systematic decomposition trends. In this work, one of these characteristicdecomposition mechanisms was again found. The final goal of these serial studies is the possibilityto provide, by the experimental evidences, a prediction model of thermal stability anddecomposition typical behavior by comparing the structural characteristics of a precipitatedcomplex.2-(2’-pyridyl)imidazole complexes with transition metal ions of general formula M(PyrIm)2(H2O)2(where M = Cu, Zn, Cd, Mn or Co) were synthesized, characterized and studied by thermoanalyticaltechniques coupled to mass spectrometry, to suggest their decomposition mechanism by evolvedgas analysis (EGA-MS).Complexes also showed the interesting possibility to be precipitated with two methanol moleculesin the structure and to replace methanol molecules with water molecules under controlledconditions.