Synthesis of rare-earth metal and rare-earth metal-fluoride nanoparticles in ionic liquids and propylene carbonate

Abstract

Decomposition of rare-earth tris(N,N′-diisopropyl-2-methylamidinato)metal(III) complexes [RE{MeC(N(iPr)2)}3] (RE(amd)3; RE = Pr(III), Gd(III), Er(III)) and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)europium(III) (Eu(dpm)3) induced by microwave heating in the ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIm][NTf2]) and in propylene carbonate (PC) yield oxide-free rare-earth metal nanoparticles (RE-NPs) in [BMIm][NTf2] and PC for RE = Pr, Gd and Er or rare-earth metal-fluoride nanoparticles (REF3-NPs) in the fluoride-donating IL [BMIm][BF4] for RE = Pr, Eu, Gd and Er. The crystalline phases and the absence of significant oxide impurities in RE-NPs and REF3-NPs were verified by powder X-ray diffraction (PXRD), selected area electron diffraction (SAED) and high-resolution X-ray photoelectron spectroscopy (XPS). The size distributions of the nanoparticles were determined by transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) to an average diameter of (11 ± 6) to (38 ± 17) nm for the REF3-NPs from [BMIm][BF4]. The RE-NPs from [BMIm][NTf2] or PC showed diameters of (1.5 ± 0.5) to (5 ± 1) nm. The characterization was completed by energy-dispersive X-ray spectroscopy (EDX).

Synthesis of plasmonic Fe/Al nanoparticles in ionic liquids

“…The [NTf 2 ] À anion was chosen because of its hydrophobic character and its hydrothermal stability, since the anion [BF 4 ] À is well known to form metal-uoride nanoparticles. 53,54 The IL cations can have a profound effect on the stabilization, size and size distribution of the obtained metal nanoparticles. 55,57 Imidazolium-ILs, in particular with the cation [BMIm] + are well established for the synthesis of small NPs.…”

“…55,57 Imidazolium-ILs, in particular with the cation [BMIm] + are well established for the synthesis of small NPs. 18,19,54,[56][57][58][59][60] However, [BMIm] + contains a slightly acidic proton in the C-2 position which can lead to metal-carbene formation. 61 The cation [BPy] + was included here because of the absence of such acidic protons.…”

Synthesis, Cytotoxicity Assessment and Optical Properties Characterization of Colloidal GdPO4:Mn2+, Eu3+ for High Sensitivity Luminescent Nanothermometers Operating in the Physiological Temperature Range

“…Moreover, in order to enhance the accuracy and reliability of temperature sensing by the minimization of the light scattering and absorption by the tissue, emission of such phosphors should spectrally fall into biological optical windows (BWs) (BW-I: 650-950 nm, BW-II: 1000-1350 nm, and BW-III: 1500-1800 nm) [15][16][17][18][19][20][21]. Therefore, many potential non-invasive nanothermometers such as YAG garnets [22], NaYF 4 fluorides [23], Au NPs [24], etc., doped with optical active ions operating in the range of BWs have been studied in the last few years. Nevertheless, these materials require difficult reaction conditions (e.g., high temperature, use of high boiling solvents) and further surface modifications to obtain biocompatible and stable nanoparticles in water solutions.…”

Pseudohalogen Chemistry in Ionic Liquids with Non‐innocent Cations and Anions

“…Besides application in classic solid state chemistry, ILs can be used as reaction media to prepare (oligomeric) metal complexes, metal organic frameworks, coordination polymers [25–35] or cluster compounds incorporating main group elements [36–41] . Within SPP 1708, the synthesis of intermetallic cluster and nanoparticles, [3,42–56] the controlled synthesis of polyanions and cations, [57–61] solvent‐free chalcogenidometal‐containing materials, [62–75] deposition of nanocrystalline materials, [76–80] ionic liquids as precursors for inorganic materials, [81–83] ionic‐liquid‐modified hybrid materials, [84–87] as well as the low‐temperature synthesis of thermoelectric materials [88–92] were investigated. Moreover, theoretical [93–106] and solubility [107–114] aspects during the synthesis process were studied.…”