Synthesis and X-ray crystal structures of a series of 3d–4f lanthanide complexes: lanthanide(III)–copper(II) coordination polymers with 2,5-pyridinedicarboxylic acid ligand

Abstract

A series of lanthanide-transition metal (Ln-M) complexes, namely, {[Ln 2 Cu(pydc) 4 (H 2 O) 3 ]ÁH 2 O} n (Ln = Tb, Eu, Sm or Gd) (H 2 pydc = 2,5-pyridinedicarboxylic acid) have been synthesized hydrothermally by selfassembly of the lanthanide ions, copper(II) ions and 2,5-pyridinedicarboxylic acid. All the complexes were characterized by physicochemical and spectroscopic methods; in addition, structural analyses revealed that all four complexes crystallized in monoclinic space group P2 1 /c. The molecular structure contains both Cu and Ln atoms, with pydc ligands bridging the four coordinate Cu(II) centers and eight coordinate lanthanide centers to form a 3-D net structure. Hence, copper is oxidized from Cu(I) to Cu(II) during the preparation. In addition, the thermogravimetric analysis of 1 is discussed. Contrary to expectations, compounds 1-3 show no photoluminescent properties.

Synthesis, structure, and antioxidative properties of a copper(II) complex with 1,2‐bis(benzimidazol‐2‐yl)ethane ligand

“…The fluorescence intensity of complex 1 is significantly weaker than that of the ligand. The quenching of the fluorescence in the Cu(II) complex is attributed to the paramagnetic nature of the transition metal involved ions …”

Poly[[octaaquatetrakis(μ3-pyridine-2,5-dicarboxylato)copper(II)diytterbium(III)] monohydrate]

“…In recent year, many studies select pyridine-2,5-dicarboxylic acid as a bridging ligand, because it offers both N-and Odonors. Thus, the carboxylate group can bond to the lanthanide, while the nitrogen atom can bond to transition metal ions, allowing the possibility of 3 d-4f heterometallic coordination polymers (Zhang et al, 2006;Yue et al, 2007;Bai et al, 2008;Chi et al, 2009;Wang et al, 2009).…”