Syntheses, Crystal structures, Magnetisms and Luminescences of two Series of Lanthanide Coordination Polymers Based on Tricarboxylic Ligand

Two series of twelve polycarboxylate lanthanide coordination polymers (CPs), namely, [Ln(cpida)(H2O)](n){Ln=La (1), Ce (2), Pr (3) and Nd (4)} and {[Ln(cpida)(H2O)]-2H(2)O}(n) {Ln=Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Ho (10), Er (11) and Yb (12)} {H(3)cpida=N( 4-carboxyphenyl) iminodiacetic acid}, have been synthesized by self-assembly and characterized by IR, TGA, X-ray crystallography, powder XRD and elemental analysis. CPs 1-4 and 5-12 are isomorphic respectively, featuring 2D double layer structures. In CPs 1-4, each metal atom connects five [cpida](3-) anions and each ligand is bound to five metal cations. However, in 5-12 each [cpida](3-) anion only connects four metal cations due to the lanthanide contraction. Further, PL spectra of CPs 6, 8 and 12 show the strong characteristic luminescence of Eu(III), Tb(III) and Yb(III) ions, respectively, suggesting that [cpida](3-) is able to sensitize the luminescence of lanthanide ions efficiently. The magnetic properties of Gd (7) and Dy (9) complexes have also been investigated.