Synthesis, structure and property of lanthanide-organic frameworks with pyridyl- and carboxylate-containing ligand

Three new lanthanide-organic frameworks {[La(IP-py)(HIP-py)(H2O)(2)]center dot H2O}(n) (1), {[Sm-2(IP-py)(2)(IP-pyH)(2)(H2O)(2)]center dot 12H(2)O}(n) (2) and {[Tb-3(IP-py)(4)(IP-pyH)(H2O)(5)]center dot 9H(2)O}(n) (3) have been prepared by reactions of the corresponding lanthanide salt with 5-(isonicotinamido) isophthalic acid (H2IP-py). The complexes have been fully characterized by means of IR, elemental analyses and single-crystal X-ray diffraction. In compounds 1-3, the lanthanide centers are eight-and nine-coordinated with different coordination geometries and the carboxylate groups of the ligand show different coordination modes leading to the formation of different 2D network structures which are well-defined by the bulky and inert functional groups. Interestingly an unprecedented 2D network of water molecules was observed in complex 2. The luminescent properties of complexes 2 and 3 were investigated. (C) 2010 Elsevier B.V. All rights reserved.