Influence of the Crystal Structure on the Luminescence Properties of Mixed Eu, La–(1, 10‐Phenanthroline) Complexes. Issue 29 (17th September 2015)

• Record Type: Journal Article
• Authors: Yang, Ting‐Hai; Fu, Lianshe; Ferreira, Rute A. S.; Nolasco, Mariela M.; Rocha, João; Carlos, Luís D.; Shi, Fa‐Nian
• Is Part Of: European journal of inorganic chemistry. Issue 29(2015)
• Page Start: 4861
• Page End: 4868
• Publication Date: 2015-09-17
• Subjects: Lanthanides -- Fluorescence spectroscopy -- Quantum efficiency -- Crystal growth; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201500611
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A series of europium Eu‐ and La‐doped complexes with two different crystal structures, namely, Eu x La1– x (phen)2 (NO3 )3 [phen = 1, 10‐phenanthroline, x = 1.0 (1 ), 0.88 (2 ), 0.73 (3 ), and 0.52 (4 )] and {[Eu x La1– x (phen)2 (H2 O)2 (NO3 )2 ](NO3 )· 2(phen)(H2 O)} [ x = 0.28 (5 ) and 0.0 (6 )], were synthesized in aqueous solution by using different Eu/La ratios.The complexes were characterized by single‐crystal and powder X‐ray diffraction, Fourier transform infrared spectroscopy, elemental analysis, thermogravimetry, and scanning electron microscopy. Compounds1 –4 and5, 6 were obtained for Eu/La molar ratios higher than 5:5 and smaller than 3:7, respectively. The photoluminescence properties of these compounds depend on the crystal structure, which is determined by the Eu/La reactant ratio. Complexes1 –4 exhibit a quantum efficiency ( η = 55 %) and quantum yield ( q = 31 %) higher than5 ( η = 23 % and q = 6 %). The photophysical properties assessed by using the LUMPAC software are in good accord with the experimental values, particularly, the calculated (26 %) and measured emission quantum yields (31 %; excitation at the ligands at 255 nm). Abstract : A series of europium Eu‐ and La‐doped complexes with two different crystal structures were synthesized in aqueous solution by using different Eu/La ratios. Eu/La ≥ 5:5 afforded a Eu(phen)2 (NO3 )3 structure (phen = 1, 10‐phenanthroline), while Eu/La ≤ 3:7 resulted in the formation of a {[La(phen)2 (H2 O)2 (NO3 )2 ](NO3 )· 2(phen)(H2 O)} structure.