Thermal stability and degradation of Co(II), Cd(II), and Zn(II) complexes with N-benzyloxycarbonylglycinato ligand

• Published in: Journal of thermal analysis and calorimetry 2010-10, Vol.102 (1), p.83-90
• Main Authors: Šumar-Ristović, Maja T., Minić, Dragica M., Poleti, Dejan, Miodragović, Zoran, Miodragović, Đenana, Anđelković, Katarina K.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Coordination compounds; Correlation; Crystal structure; Crystallization; Degradation; Differential scanning calorimetry; Enthalpy; Exact sciences and technology; Inorganic Chemistry; Inorganic chemistry and origins of life; Ligands; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Preparations and properties; Thermal stability
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-010-0748-2

Thermal behavior of Co(II), Cd(II), and Zn(II) complexes with N -benzyloxycarbonylglycinato ligand was investigated using the results of TG, DSC and DTG analysis obtained at different heating rates (2.5 to 30 °C min −1 ), from room temperature to about 900 °C. Mechanisms of complex degradation, as well as enthalpies of the degradation processes were determined. It is shown that thermal stability of investigated complexes correlates with their crystal structures, especially with the presence of crystallization and coordinated water molecules. The values of dehydration enthalpies are discussed and correlated with composition of the complexes. Kissinger’s, Ozawa’s, and Friedman’s isoconversion methods were used for the determination of kinetic parameters: the pre-exponential factor A and the apparent activation energy E a . For all three complexes and all steps of degradation, the values of kinetics parameters obtained by Kissinger’s and Ozawa’s methods are in good agreement. The results obtained by Friedman’s method showed that some decomposition steps are simple and some others are complex ones.