A series of lanthanide-transition metal coordination polymers with mixed ligands: syntheses, structures, photoluminescence and magnetic properties

Six unusual lanthanide-transition metal compounds, [Ln(2)M(1,3-bdc)(4)(TPA)(H2O)]center dot nH(2)O (n = 2, Ln = Y, M = Co 1; n = 2, Ln = Y, M = Zn 2; n = 2, Ln = Er, M = Co 3; n = 2, Ln = Er, M = Zn 4; n = 0.5, Ln = Sm, M = Co 5) and [Y2Ni2(1,3-bdc)(5)(TBA)(H2O)(3)]center dot 7H(2)O 6, where 1,3-H(2)bdc = benzene-1,3-dicarboxylic acid, TPA = tris(2-pyridylmethyl)amine and TBA = tris(2-benzimidazolylmethyl)amine, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses. Compounds 1-5 are isomorphous, and crystallize in the space group P2(1)/c. In 1-5, the Ln atoms are connected by 1,3-bdc anions to form 2D layer structures, where the terminal M(TPA)(1,3-bdc) units are attached to both sides of the 2D layers. In compound 6, the Y atoms are connected by 1,3-bdc anions to form a 1D double chain structure. In addition, the photoluminescence and variable-temperature magnetic susceptibility of the compounds have been studied.