Structures and Properties of Luminescent Pentanitratoeuropate(III) Ionic Liquids. Issue 3 (16th December 2014)

• Record Type: Journal Article
• Authors: Zhao, Ying; He, Ling; Tang, Ning; Qin, Song; Tao, Guo‐Hong; Liang, Fu‐Xin
• Is Part Of: European journal of inorganic chemistry. Issue 3(2015)
• Page Start: 542
• Page End: 551
• Publication Date: 2014-12-16
• Subjects: Rare earths -- Ionic liquids -- Lumines­cence -- Colorimetric purity -- Structure elucidation; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201403018
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A series of luminescent ionic liquids based on pentanitratoeuropate(III) anions combined with imidazolium cations, namely, 1, 2, 3‐trimethylimidazolium {[MC1 mim]2 [Eu(NO3 )5 ] (1)}, 1, 3‐dimethylimidazolium {[C1 mim]2 [Eu(NO3 )5 ] (2)}, 1‐ethyl‐3‐methylimidazolium {[C2 mim]2 [Eu(NO3 )5 ] (3)}, 1‐butyl‐3‐methylimdazolium {[C4 mim]2 [Eu(NO3 )5 ] (4)}, 1‐hexyl‐3‐methylimidazolium {[C6 mim]2 [Eu(NO3 )5 ] (5)}, and 1‐methyl‐3‐octylimidazolium {[C8 mim]2 [Eu(NO3 )5 ] (6)}, were synthesized. These complexes were characterized by NMR and IR spectroscopy as well as elemental analysis. They exhibit high thermostability and wide liquidus ranges of more than 300 °C. Colorless plate crystals of 1 were isolated, and the crystal structure was determined by single‐crystal X‐ray diffraction [monoclinic system, C 2/ c space group with the cell parameters a = 21.6870(6) Å, b = 9.9807(4) Å, c = 15.0267(6) Å, β = 131.140(4)°, Z = 4]. In the [Eu(NO3 )5 ] 2– anion, the 10‐coordinate Eu III ion is coordinated by five bidentate nitrate ligands and has a highly symmetrical trigonal‐bipyramidal geometry. Compounds 1–6 exhibit bright red luminescence of high colorimetric purity. Only two characteristic narrow monochromatic bands, arising from the 5 D0 → 7 F J ( J = 1 and 2) intraconfigurational f–f transitions, were clearly observed in their emission spectra at 298 K. The intense red photoluminescence is still stable at 150 °C. These 10‐coordinated Eu III complexes are of interest as potential thermally stable luminescent soft materials. Abstract : A series of luminescent ionic liquids based on pentanitratoeuropate (III) anions are synthesized and characterized. These complexes exhibit high thermostability and a wide liquidus range. The 10‐coordinate [Eu(NO3 )5 ] 2– anion has a highly symmetric trigonal‐bipyramidal structure. Complexes1 –6 exhibit bright red luminescence with narrow‐band and intense emission of high colorimetric purity.