Two novel complexes ([Ln(3,5-Dipr-2-OHBA)(3)(phen)](2) (Ln = Dy(1), Yb(2); 3,5-Dipr-2-OHBA = 3,5-diisopropylsalicylic acid; phen = 1,10-phenanthroline)) were synthesized and characterized by elemental analysis, conductivity measurements, IR spectra, single crystal X-ray diffraction, and thermogravimetric differential scanning calorimetry/Fourier transform infrared (TG/DSC-FTIR) technology. The fluorescent property of complex I was also studied. The two binuclear complexes are isostructural. Each Ln(3+) ion is octa-coordinated, yielding a trigondodecahedron conformation. The thermal properties of the title complexes were investigated by simultaneous TG/DSC-FTIR techniques. The kinetic parameters of the first decomposition stage for the complexes were calculated by the integral isoconversional nonlinear method (NL-INT method), Starink method, Kissinger's method, and Ozawa-Doyle's method. The thermodynamic parameters (Delta H-not equal, Delta G(not equal), and Delta S-not equal) at the peak temperatures of the DTG curves were also calculated. Heat capacities of the two complexes were measured by DSC. The values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. Besides, the smoothed heat capacities and thermodynamic functions (H-T - H-298.15K), (S-T - S-298.15K), and (G(T) - G(298.15K)) were calculated.