¹ Department of Chemistry, Northwest University and Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Xi'an, Shaanxi 710069, China
² College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, China

Europium(III) compound with 2-oxopropionic acid salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) and 1,10-phenanthroline (C₁₂H₈N₂, phen) has been prepared. A yellow prismatic crystal of the compound was obtained, and the molecule crystallized in the triclinic space group P-1. There are two 9-coordinated complex molecules in every structure unit, where every Eu atom is coordinated by three water molecules and two tridentate C₁₀H₁₀N₂O₄ ligands, forming two stable pentacycles. The coordination polyhedron around Eu³⁺ was described as a single cap square antiprism. In the crystal cell, there are one free 1,10-phenanthroline and four water molecules. The thermal decomposition of the compound and its kinetics were studied by non-isothermal thermogravimetry. The Kissinger’s method and Ozawa’s method were used to calculate the activation energy value of the first-step decomposition. The stages of the decompositions were identified by TG-DTG-DSC curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equations were investigated by comparing the kinetic parameters.