Syntheses, Structures, and Photoluminescent Properties of Lanthanide Coordination Polymers Based on a Zwitterionic Aromatic Polycarboxylate Ligand

Three series of lanthanide coordination polymers, {[Ln(L)(H2O)2]·NO3·2H2O }n (Ln = La 1, Pr 2), {[Ln2(L)2(NO3)(H2O)2]·Cl·6H2O}n (Ln = Nd 3), {[Ln(L)(H2O)2]·Cl·3H2O}n (Ln = Sm 4, Eu 5, Gd 6, Tb 7, Dy 8, Ho 9, Er 10, Tm 11, Yb 12, and Lu 13) (H3L = 4-carboxy-1-(3,5-dicarboxy-benzyl)-pyridinium chloride), have been successfully synthesized under hydro(solvo)thermally conditions. Single-crystal X-ray diffraction analyses revealed that compounds 1–3 all crystallize in triclinic space group P1, but they display different three-dimensional structures with diverse dinuclear subunits. In contrast, compounds 4–13 display the same layer structures in the triclinic space group P1. The structural difference of these two classes of compounds is derived from the effect of lanthanide contraction. Powder X-ray diffraction (PXRD) and thermogravimetric analyses of compounds 1–13 have also been investigated and discussed in detail. The solid-state luminescent properties of compounds 4, 5, 7, and 8 were characterized, and t...