title: Visible and NIR photoluminescence properties of a series of novel lanthanide-organic coordination polymers based on hydroxyquinoline-carboxylate ligands.
abstract: A series of novel two-dimensional (2D) lanthanide coordination polymers with 4-hydroxyquinoline-2-carboxylate (H(2)hqc) ligands, [Ln(Hhqc)(3)(H(2)O)](n)·3nH(2)O (Ln = Eu (1), Tb (2), Sm (3), Nd (4), and Gd (5)) and [Ln(Hhqc)(ox)(H(2)O)(2)](n) (Ln = Eu (6), Tb (7), Sm (8), Tm (9), Dy (10), Nd (11), Yb (12), and Gd (13); H(2)ox = oxalic acid), have been synthesized under hydrothermal conditions. Complexes 1-5 are isomorphous, which can be described as a two-dimensional (2D) hxl/Shubnikov network based on Ln(2)(CO(2))(4) paddle-wheel units, and the isomorphous complexes 6-13 feature a 2D decker layer architecture constructed by Ln-ox infinite chains cross-linked alternatively by bridging Hhqc(-) ligands. The room-temperature photoluminescence spectra of complexes Eu(III) (1 and 6), Tb(III) (2 and 7), and Sm(III) (3 and 8) exhibit strong characteristic emissions in the visible region, whereas Nd(III) (4 and 11) and Yb(III) (12) complexes display NIR luminescence upon irradiation at the ligand band. Moreover, the triplet state of H(2)hqc matches well with the emission level of Eu(III), Tb(III), and Sm(III) ions, which allows the preparation of new optical materials with enhanced luminescence properties.
authors.affiliation: State Key Laboratory of Structure Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Gai
authors.forename: Ke-Cai
authors.initials: KC
authors.lastname: Xiong
authors.forename: Lian
authors.initials: L
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Bu
authors.forename: Xing-Jun
authors.initials: XJ
authors.lastname: Li
authors.forename: Fei-Long
authors.initials: FL
authors.lastname: Jiang
authors.forename: Mao-Chun
authors.initials: MC
authors.lastname: Hong
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004355:Drug Stability; D006912:Hydroxyquinolines / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D008027:Light; D049449:Luminescence; D009942:Organometallic Compounds / Q000737:chemistry*; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D006912:Hydroxyquinolines; D028581:Lanthanoid Series Elements; D008024:Ligands; D009942:Organometallic Compounds; D011108:Polymers; C034010:4-hydroxyquinoline