title: Construction of four low-dimensional NIR-luminescence-tunable Yb(III) complexes.
abstract: Four low-dimensional ytterbium(iii)-organic compounds through hydrothermal reactions of quinoline-2,3-dicarboxylic acid (2,3-H2qldc) and oxalic acid (H2ox) with Yb2O3, namely, [Yb(2,3-qldc)(ox)1/2(H2O)3·(H2O)4]n (1), [Yb(2,3-qldc)(ox)1/2(H2O)2·(H2O)2]n (2), [Yb(2,3-Hqldc)(ox)(H2O)2·(H2O)]n (3) and [Yb(2,3-Hqldc)(ox)(H2O)·(H2O)2]n (4), were first synthesized and characterized by elemental analysis (EA), infrared spectroscopy (IR), thermogravimetric analysis (TG), and single-crystal X-ray diffraction. When the reactant ratio of 2,3-H2qldc : H2ox : Yb2O3 is 2 : 1 : 1, 1-D chain-like complex 1 with three coordinated water molecules around the Yb(iii) ion was obtained in mixed solvents of H2O and CH3OH (v : v = 10 : 1) at 70 °C, and with the increase of temperature to 100 °C, the same reactants gave 2-D 6(3) topological layer-like complex 2 with two coordinated water molecules in the coordination sphere of the Yb(iii) ion. However, when the reactant ratio was changed to 1 : 1 : 1, two 2-D 6(3) topological layer-like complexes 3 (70 °C) and 4 (100 °C) were obtained at different temperatures, in which the coordination water molecules in 3 and 4 are two and one, respectively. Obviously, these results reveal that the reaction temperature and reactant ratios play critical roles in the structural direction of these low-dimensional compounds. Interestingly, with the gradual loss of coordination water molecules to the Yb(iii) ion, the near infrared (NIR) emission of four Yb(iii)-based compounds 1-4 can be gradually strengthened with increasing order of 1 < 3 < 2 < 4, indicating that these ytterbium(iii) complexes have tunable near infrared luminescence.
authors.affiliation: School of Chemistry and Environment, South China Normal University, Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Guangzhou 510006, PR China. caiyp@scnu.edu.cn.
authors.forename: Zhi-Peng
authors.initials: ZP
authors.lastname: Zheng
authors.forename: Xiu-Xia
authors.initials: XX
authors.lastname: Zhang
authors.forename: Teng
authors.initials: T
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Lei-Ming
authors.initials: LM
authors.lastname: Wei
authors.forename: Li-Guo
authors.initials: LG
authors.lastname: Zhang
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Lin
authors.forename: Yue-Peng
authors.initials: YP
authors.lastname: Cai
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry*; D008163:Luminescent Measurements; D008958:Models, Molecular; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared; D013696:Temperature; D013818:Thermogravimetry; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D015018:Ytterbium