Thermochemical Properties of the Complexes RE(HSal)3·2H2O(RE = La, Ce, Pr, Nd, Sm)

Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(HSal)3·2H2O(RE = La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes, ΔcU, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, ΔcHmθ, and standard molar enthalpies of formation, ΔfHmθ, were calculated.