A new tripod polyaromatic acid ligand H3TCM（H3TCM={2,4,6-tris1,3,5-trimethylbenzene}） and its binuclear rare earth complex \·2DMF were prepared and the structure of complex was characterized by single crystal X-ray diffraction. The complex crystallizes in triclinic crystal system, space group P1 with a=1.123 3（2） nm, b=1.374 1（2） nm, （c=）1.731 8（2） nm, α=78.19（1）°, β=80.02（1）°, γ=80.08（1）°, V=2.550 8（7） nm3, Z=1, （R=）0.035 8, wR=0.080 3. Two TCM ligands that are both in cis, cis, cis-conformations adopt face-to-face orientation and are joined together by two La3+ to a novel binuclear cage-like structure. Two DMF molecules are encapsulated in this cage by coordination. In addition, the other two free DMF molecules are embedded in the channels from the packing of these units along a and b axises.
A new binuclear cage-like complex, [Eu2(TCM)2(DMSO)6]·2DMSO, was synthesized via the reaction of H3TCM(H3TCM={2,4,6-tris[(2-carboxyphenoxy)methyl]-1,3,5-trimethylbenzene}) and Eu3+. Single crystal X-ray diffraction study reveals a centro symmetric binuclear neutral entity, space group P21/c with a=1.5188(2) nm, b=1.7135(3) nm, c=1.7578(2) nm, β=95.34(2)°, V=4.5549(9) nm3, Z=4. In the complex, Eu3+ metal centers are bridged together by mono- and bidentate carboxylate groups from two ligands. The most interesting fact is that the size of solvent molecules has a great influence on the binuclear cage-like complex in the shape of binuclear cage, the coordination mode of carboxylate group and the coordination number of Eu3+.
