title: Synthesis, structure and properties of 2D lanthanide coordination polymers based on N-heterocyclic arylpolycarboxylate ligands.
abstract: The reaction of 3-(2,4-dicarboxyphenyl)-2,6-pyridinedicarboxylic acid (H4dppd) with rare earth nitrates under hydrothermal conditions generated a series of new two-dimensional (2D) coordination polymers, namely {[La(Hdppd)(H2O)2·(H2O)2]n (1), [Ln2(Hdppd)2(H2O)4·(H2O)3]n [Ln = Sm (2), Eu (3)] and [Ln(Hdppd)(H2O)3·H2O]n [Ln = Gd (4), Tb (5), Dy (6), Ho (7), Er (8)] [Hdppd = 3-(2,4-dicarboxyphenyl)-2,6-pyridinedicarboxylic trivalent anion]}. The complexes were characterized by X-ray single-crystal diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Luminescence spectroscopy of 3 and 5 showed bright red and green luminescences due to the 4f(n)-4f(n) transitions in Eu(3+) and Tb(3+) respectively, although the luminescence lifetime is shortened by non-radiative decay due to the presence of coordinating water molecules. The magnetic properties of 2-8 were measured and discussed. Compound 6 exhibits frequency dependent out-of-phase signals, and ferromagnetic coupling exists in 8.
authors.affiliation: Laboratory of Coordination Chemistry, Shenyang University of Chemical Technology, Shenyang 110142, People's Republic of China. sunyaguang@yahoo.com.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: You
authors.forename: Shu-Ju
authors.initials: SJ
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Xiong
authors.forename: Fu
authors.initials: F
authors.lastname: Ding
authors.forename: Katrien W
authors.initials: KW
authors.lastname: Meert
authors.forename: Dirk
authors.initials: D
authors.lastname: Poelman
authors.forename: Philippe F
authors.initials: PF
authors.lastname: Smet
authors.forename: Bao-Yi
authors.initials: BY
authors.lastname: Ren
authors.forename: Yan-Wen
authors.initials: YW
authors.lastname: Tian
authors.forename: Ya-Guang
authors.initials: YG
authors.lastname: Sun