Preparation and study of thermal decomposition mechanism of Zn(Thr)(AcO)2·2H2O

The complex of Zn(AcO)2·2H2O and threonine was prepared in the mixture solvent of water-acetone, the composition of which was identified as Zn(Thr)(AcO)2·2H2O by chemical and elemental analyses. The complex was investigated by XRD, JR, TG-DTG and DSC methods. The result of TG-DTG shows that the thermal decomposition processes of the complex can be divided into three stages, which were dehydration (I), partial decomposition (II) and complete decomposition into ZnO (III). Dehydration enthalpy was 126.89 kj·mol−1, decomposition enthalpy of the stage (II) was 79.50 kJ·mol−1. The study of non-isothermal kinetics shows that the mechanism of the dehydration stage was Maple Power of n=3/2, the apparent activation energy E was 145.32 kJ·mol−1 and the pre-exponential factor A was 1.4125×1017 s−1, and that of ligand-losting process was nucleation and growth mechanism (Avrami-Erofeev equation n=1/2), its E was 189.33 kJ·mol−1, and A was 3.4674×s−1. The empirical kinetics model equations of the investigated processes were proposed.