A new rare earth organic complex with a double interleaved structure, namely [Sm(BDC)_1.5(DMF)(H₂O)]_n (H₂BDC = 1,4-benzenedicarboxylic acid, DMF = N,N΄-dimethyl formamide) was synthesized. The crystal structure is of triclinic, space group P with a = 8.6343(6), b = 10.1470(5), c = 11.2073(6) Å, α = 65.495(5), β = 71.626(5), γ = 78.130(5)°, V = 844.70(9) ų, C₁₅H₁₅NO₈Sm, M_r = 487.64, Z = 2, D_c = 1.917 g/cm³, F(000) = 476, μ = 3.519 mm^-1, R = 0.0380 and wR = 0.0864 for 3504 observed reflections (I > 2s(I)). The structure has been determined by single-crystal X-ray diffraction analyses and displays a 2-fold interpenetrated 3D network with the classical pcu topology. The compound was analyzed by X-ray powder, infrared spectroscopy, thermogravimetric analysis and fluorescent spectroscopy. The fluorescent property makes it a good candidate for photoactive materials.