A series of new complexes, [Ln (2,4-DMBA)(3)(5,5 '-DM-2,2 '-bipy)](2) (Ln = Sm(1), Eu (2)), [Pr (2,4-DMBA)(3) (5,5 '-DM-2,2 '-bipy)](2)center dot 0.5(C2H5OH) (3), [Ln (2,4-DMBA)(3) (5,5 '-DM-2,2 '-bipy)](2)center dot 0.5(2,4-DMBAH)center dot 0.25(5,5 '-DM-2,2 '-bipy) (Ln = Tb (4), Dy (5)) (2,4-DMBA = 2,4-dimethylbenzoate, 5,5 '-DM-2,2 '-bipy = 5,5 '-dimethy-2,2 '-bipyridine) were synthesized via hydrothermal reaction conditions. The complexes were characterized through elemental analysis, Infrared spectra (IR), Raman (R) spectra, UV-Vis spectra, single X-ray diffraction. Single crystal data show that complexes 1-5 are binuclear complexes, but they can be divided into three different crystal structures. The thermal decomposition mechanism of complexes 1-5 were investigated by the technology of simultaneous TG/DSC-FTIR. What's more, the luminescent properties of complexes 1-2 and 4 were discussed, and the luminescence lifetime (tau) of complexes 2 and 4 were calculated.</p>