Two novel lanthanide complexes with the general formula [Ln(2-Br-5-MOBA)3(2,2'-DIPY)](2) (Ln = Pr(1), Dy(2); 2-Br-5-MOBA = 2-bromine-5-methoxybenzoate; 2,2'-DIPY = 2,2'-bipyridine) have been successfully synthesized and characterized. The complexes 1 and 2 are isostructural and nine-coordinated with distorted monocapped square antiprismatic coordination geometry by the single-crystal X-ray diffraction analyses. Two complexes are all assembled into the 1D, 2D, 3D supramolecular structures by C-H center dot center dot center dot O hydrogen bonding and pi-pi stacking interactions. The thermal decomposition mechanism for title complexes were obtained by TG/DSC-FTIR technology. The molar heat capacities of the complexes 1 and 2 are measured by a DSC instrument over the temperature range from 263.15 K to 365.15 K. On the basis of the fitted polynomial and thermodynamic equations, the smoothed values of heat capacities and thermodynamic functions (H-T-H-298,(15K)), and (S-T-S-298.15K) of the two complexes are calculated. In addition, the fluorescence spectra indicate that the complex 2 exhibits the characteristic emission of Dy(III) ion (F-4(9/2) -> H-6(13/2-15/2)). (C) 2017 Elsevier Ltd.