Syntheses, crystal structures and characterizations of six coordination polymers from reduced Schiff base ligands

Six coordination polymers from reduced Schiff base ligands, namely, [Zn(L1)2]·2H2O (1), [Ni(L1)2]·2H2O (2), [Ni(L1)2(H2O)2] (3), [Zn(L2)2]·H2O (4), [Ni(L2)2]·0.5H2O (5), and [Co(L2)2(HL2)] (6) (HL1 = 4-((4-pyridinylmethyl)amino)benzoic acid, HL2 = 3-((4-pyridinylmethyl)amino)benzoic acid) have been obtained by hydrothermal method and studied by single crystal X-ray diffraction, elemental analyses, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Compounds 1 and 2 are isostructural while compounds 4 and 5 also are isostructural. All these four compounds exhibit a 2D layer structure. Compound 2 is isomeric to 3 but has a chain structure. Compound 6 also exhibits a chain structure. The photoluminescence properties of compounds 1 and 4 were studied.