Abstract: Two new complexes [Nd(oba)(Hoba)(H₂O)₂]·H₂O(1) and Sm(oba)(Hoba)(phen)(2)(H₂oba=4,4'-oxybis(benzoic acid),phen=1,10-phenanthroline) were prepared by hydrothermal method.The X-ray diffraction analysis indicated that the two complexes crystallized in monoclinic system with space group C2/c.The cell parameter of complex 1 are:a=2.736 80(5) nm,b=0.956 35(2) nm,c=2.170 93(4) nm,β=97.685 0(10)°,V=5.631 02(19) nm³,Z=8,F(000)=2 854,R(int)=0.022 6.In complex 1,oba and Hoba ligands connect the neighboring Nd³⁺ ions to form a 2D network with novel topology of{4²·6}{4³·6·8⁴·10²}{4}.Each Nd³⁺ ion is eight-coordinated by six oxygen atoms from oba and Hoba ligands and two O atoms from waters.3D structure is achieved through O——H…O hydrogen bondings between the coordinated water molecules and Hoba and between Hoba ligands.The cell parameters of complex 2 are:a=1.352 60(5) nm,b=1.936 86(6) nm,c=2.728 59(8) nm,β=99.867(2)°,V=7.042 6(4) nm³,Z=8,F(000)=3 368,R(int)=0.039 4.In complex 2,the coordination modes of oba and Hoba are similar to those in complex 1.Sm³⁺ ion is eight-coordinated by six O atoms from oba and Hoba ligands and two N atoms from phen.The two neighboring Sm³⁺ ions are connected by COO^- groups and form dimeric units,which are further joined by oba lignds to assemble into a 1D chain-like complex.The 2D network of complex 2 is formed through the hydrogen bondings between the uncoordinated carboxyl of the Hoba ligands.Moreover,3D superamolecular structure of complex 2 is formed through the π-π stacking interactions between phen molecules.The UV Vis spectrum of complex 1 shows characteristic transitions of Nd³⁺ with ⁴I_9/2→⁴G_7/2+⁴G_9/2+²K_13/2 and ⁴I_9/2→⁴G_5/2+⁴G_7/2 at 510~538 nm and 566~600 nm,respectively;the fluorescence spectrum of complex 2 shows characteristic emission of Sm³⁺ with the transitions of ⁴G_5/2→⁶H_5/2,⁴G_5/2→⁶H_7/2 and ⁴G_5/2→⁶H_9/2.