A series of 3-D lanthanide coordination polymers constructed from dinuclear building blocks: Synthesis, structure, thermal stability, and fluorescent properties

A series of novel coordination polymers [Ln(2)(NIPH)(2)(Suc)(H2O)(2)] [Ln = Tb(1), Eu(2), Gd(3), Dy(4), Ho(5), Er(6), Tm(7) and Y(8); H2NIPH = 5-nitroisophthalic acid; H(2)Suc = succinic acid] have been synthesized by the reaction of nitrate salts of Ln (III) with 5-nitroisophthalic acid and succinic acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analyses reveal that all eight complexes have 3-D structures, and in these complexes, they were crystallized in monoclinic space group C2/c. Two crystallographically equivalent Ln atoms are bridged by two especial carboxylate groups in chelating/bridging bidentate fashion to give a dinuclear lanthanide building block [Ln(2)O(2)(CO2R)(8)] with shorter separations of Ln center dot center dot center dot Ln. Those blocks are interconnected to each other leading to a 1-D infinitely extending chain, and then these chains are linked to each other through the NIPH to a 2-D open framework, which further link to each other to form 3-D networks. The thermogravimetric analysis of 1-8 and photoluminescent properties of 1 and 2 are discussed in detail. (C) 2010 Elsevier B.V. All rights reserved.