Synthesis, crystal structures, fluorescence, and magnetic properties of 1,3,5-benzenetricarboxylate coordination polymers

Abstract

Four new coordination polymers, {[Mn3(BTC)2(4-pp)6(H2O)2]·(4-pp)2(H2O)2}n 1, [Cu3(BTC)2(dpa)2]n 2, {[Zn3(BTC)2(4-pp)6]·(H2O)}n 3, and [Ag2(HBTC)(Pz)1/2]n 4, were synthesized under pH-controlled solvothermal conditions with symmetrical polycarboxylic acid of 1,3,5-benzenetricarboxylic acid (H3BTC) and nitrogen-containing heterocyclic compounds, pyrazine (pz), 4-phenylpyridine (4-pp), and 4,4′-dipyridylamine (dpa). Complexes 1–4 were characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra, powder X-ray diffraction, thermal gravimetric analysis, photoluminescence, and magnetic susceptibility. Complexes 1 and 3 show two-dimensional (2-D) layered structures, 2 exhibits a three-dimensional (3-D) network structure, and 4 is a one-dimensional (1-D) polymeric chain structure. Magnetic susceptibility measurements indicate that 1 shows weak antiferromagnetic coupling between MnII ions and 2 exhibits ferromagnetic interaction between CuII ions. The photoluminescence properties of 3 and 4 are similar to the ligand H3BTC.