A Series of Novel Ln−Succinate−Oxalate Coordination Polymers: Synthesis, Structure, Thermal Stability, and Fluorescent Properties

Abstract

A series of novel coordination polymers [Ln(suc)(ox)0.5(H2O)] (Ln = Sm (1) and Tb (2)); [Pr(suc)(ox)0.5(H2O)2]·2H2O (3); and [KLn(suc)0.5(ox)1.5(H2O)]·H2O (Ln = Nd (4), Eu (5), Tb (6) and Gd(7)) have been synthesized by the reaction of nitrate salts of Ln(III) with succinic acid and oxalic acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analyses reveal that all seven complexes have 3D net structures, and in these complexes, they were crystallized in triclinic space group P1̅ for complexes 1 and 2, orthorhombic space group Fddd for complex 3, and orthorhombic space group Pbam for complex 4−7, respectively. In particular, for 4−7, K ions were introduced into the structures of complexes and made the structures more novel and complicated. Thus the complexes have the same ligands but different structures. The results show that coordination modes of the linear succinic acid and oxalic acid ligands are versatile and can adopt different conformations according to different lanthanide ions. The thermogravimetric analysis of 1−7 and photoluminescent properties of 2, 5 and 6 are discussed in detail.