Synthesis, Crystal Structures and Thermal Stabilities of Lanthanide Coordination Polymers with 5-Nitroisophthalate

Abstract

Two new lanthanide coordination polymers, namely, [Ho(ox)0.5(nip)(H2O)3]·2H2O (1) and [Gd(nip)(Hnip)(phen)] (2) (nip = 5-nitroisophthalate, ox = oxalate and phen = 1,10-phenanthroline) were synthesized under hydrothermal conditions. They crystallize in triclinic, P−1 space group and exhibit 1D structure features: complex 1 possesses a 1D parallel ladder structure bridged by oxalate and nip anions and compound 2 has 1D loop-like chain structure. Moreover, intermolecular attractions such as H-bonds and π–π stacking result in the high-dimensional supramolecular frameworks. The different coordination modes of the nip anions, the appropriate choice of multidentate bridging ligands and the intermolecular forces affect the topological structures. In addition, the thermal behavior of the complexes is investigated in air.