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 4I9/2→4G7/2+4G9/2+2K13/2 and 4I9/2→4G5/2+4G7/2 at 510~538 nm and 566~600 nm, respectively;The fluorescence spectrum of complex 2 shows characteristic emission of Sm3+ with the transitions of 4G5/2→6H5/2, 4G5/2→6H7/2和4G5/2→6H9/2.

Key words: lanthanide complex, oxybis(benzoic acid), crystal structure, supramolecular