871949-37-0Relevant academic research and scientific papers
Synthesis, structure and luminescence properties of four novel terbium 2-fluorobenzoate complexes
Li, Xia,Zhang, Zhuo-Yong,Zou, Ying-Quan
, p. 2909 - 2918 (2005)
Four new complexes [Tb(2-FBA)3·(2-HFBA)·H 2O]2 (1), {[Tb(2-FBA)3·(4,4′-bpy) ·H2O]3}n (2), [Tb(2-FBA) 3·(2,2′-bpy)]2 (3), and [Tb(2-FBA) 3·phen·CH3CH2OH] 2·[Tb(2-FBA)3·phen]2 (4) (2-HFBA: 2-fluorobenzoic acid; 4,4′-bpy: 4,4′-bipyridine; 2,2′-bpy: 2,2′-bipyridine; phen: 1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction analysis. Complex 1 is a dimeric molecule with a one-dimensional supramolecular structure formed by hydrogen bonds. Complex 2 is an infinite one-dimensional polymer chain formed by bridging carboxylato groups; its 2D framework structure is formed by hydrogen bonds. The structure of complex 3 contains three independent binuclear molecules in the asymmetric unit. In two of them, two Tb3+ ions are held together by four 2-FBA groups, with two of them in a bidentate-bridging mode and the other two in a chelating-bridging mode. In the third, two Tb3+ ions are held together by four 2-FBA groups, all of which are in the bidentate-bridging mode. One 2-FBA group and one 2,2′-bpy chelate to one Tb3+ ion, resulting in coordination numbers of the central terbium ion of nine and eight, respectively. The structure of complex 4 contains two nonequivalent binuclear molecules in the asymmetric unit - [Tb(2-FBA)3·phen· CH3CH2OH]2 and [Tb(2-FBA)3· phen]2. In the former, the Tb3+ ion is surrounded by eight atoms, five O atoms from five 2-FBA groups, one O atom from one ethanol molecule and two N atoms from phen, and the 2-FBA groups act in monodentate and bridging coordination modes. In the latter, the Tb3+ ion is coordinated by nine atoms, seven O atoms from five 2-FBA groups and two N atoms of phen, and the 2-FBA groups link the Tb3+ ion in chelating, bridging, and chelating-bridging coordination modes. Complexes 1, 3, and 4 emit a bright green light under UV light in the solid state. There are four emission peaks in the luminescence spectra at 488, 543, 584, and 618 nm, corresponding to the 5D4→7F6, 5D4→7F5, 5D 4→7F4, and 5D 4→7F3 transitions, respectively, of the Tb3+ ion. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
