A Reusable Eu³⁺ Complex for Naked‐Eye Discrimination of Methanol from Ethanol with a Ratiometric Fluorimetric Equilibrium in Methanol/Ethanol Mixtures

Abstract

Immediate naked eye distinction of methanol from ethanol can be performed by simple dissolution, in each of these solvents, of either [Na][EuFOD 4 ] (1) complex or in mixture of products from the reaction between [P 6,6,6,14 ][Eu(FOD) 4 ] and NaOPhMe 3 , referred as 2, ([P 6,6,6,14 ] + = trihexyltetradecylphosphonium cation, FOD -= 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate). Additionally, an easy, low-cost, efficient and fast spectrofluorimetric method for the detection and [a]

Lanthanide Metal–Organic Framework Isomers with Novel Water-Boosting Lanthanide Luminescence Behaviors

“…From the single-crystal analysis, the initial QXBA-Eu-2 owned coordinated DMA molecules with Eu 3+ centers, revealing the high level of asymmetry around the Eu 3+ centers. As shown in Figure a, due to the “crystal field effect” of the Eu 3+ , the lower symmetry sites induced the emission bands of 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions splitting into a doublet. , The excitation spectra were identical with the solid-state UV–vis adsorption spectra (Figure b). Meanwhile, the emission band of QXBA was still observed, revealing that the “antenna” effect was not fully effective (Figure a).…”

Dual-Channel Luminescent Signal Readout Strategy for Classifying Aprotic/Protic Polar Organic Medium and Naked-Eye Monitoring of Water in Organic Solvents

“…The cause of the splitting of the 5D 0 → 7F 2 transition band was considered to be due to the "crystal field effect" of the Eu 3+ and defined bands at 614 and 622 nm. 31 As for free R6G, a broad peak was located at around 550 nm. As expected, the fluorescence spectra of R6G@Eu-MOF simultaneously exhibited characteristic emission of R6G and Eu-MOF upon 350 nm excitation (Figure 2c).…”

“…Eu-MOF displayed the characteristic emission peaks at 592, 614, and 622 nm, corresponding to the typical 5D 0 → 7F J ( J = 1, 2) transition. The cause of the splitting of the 5D 0 → 7F 2 transition band was considered to be due to the “crystal field effect” of the Eu 3+ and defined bands at 614 and 622 nm . As for free R6G, a broad peak was located at around 550 nm.…”

Multifunctionality of the [C2mim][Ln(fod)4] series (Ln = Nd–Tm except Pm): magnetic, luminescence and thermochemical studies

“…Two of the most explored properties of the Ln are their optical and magnetic properties. The luminescent properties of the Ln 3+ ions cover a wide range of emissions comprising near-infrared (Pr 3+ , Nd 3+ , Ho 3+ , Er 3+ , Yb 3+ , Tm 3+ ,), visible (Pr 3+ , Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ , Tm 3+ ) and ultraviolet (Gd 3+ ), which combined to the narrowness and the hypersensitivity of their transitions have allowed their use in many applications including thermometers, 5,6 sensing of gases, vapours or small molecules, 7–10 light-emitting devices, 11,12 biomedical applications, 13,14 forensics, 15 etc. The luminescence properties of the Ln family are so unique that they have become indispensable in the developments in all fields of optics.…”

“…26 By reacting [P 6,6,6,14 ][Eu(fod) 4 ] with NaOPhMe 3 the reversal of thermochromism, with temperature decrease, is hindered and the resulting reaction mixture can be used in an easy, low-cost and efficient ratiometric method in the detection and quantification of methanol in mixtures with ethanol. 27 Keeping the [Eu(fod) 4 ] − anion we prepared the solid salt [chol][Eu(fod) 4 ] (chol = choline), which showed a self-reference ratiometric thermal behaviour that functions at temperatures up to 368 K, not using the commonly reported temperature-dependent luminescence intensity but instead using transitions to two crystal-field sublevels of the same electronic level of the 5 D 0 → 7 F 2 transition. 6 When confined in a polysulfone membrane, this effect is lost although the luminescence intensity presented a temperature-dependency with a linear fit from 333 to 393 K and a quantum yield, φ , of 54% at room temperature.…”