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Europium‐Based Ionic Liquids as Luminescent Soft Materials

“…For a hydrated Eu 3+ species, an even lower intensity ratio and an asymmetry factor of approximately 0.63 would be expected. [23] Water entering the coordination sphere of the oxophilic lanthanide center has long been noted to have a strong influence on the luminescent properties of lanthanides in ionic liquids. It typically leads to reduced lifetimes for the excited state and eventually to total quenching of any emission.…”

Europium‐basierte ionische Flüssigkeiten als lumineszierende weiche Materialien

“…3.49 für festes und flüssiges 2 mit Werten für das Eu 3+ ‐Ion in unterschiedlichsten Umgebungen,22 so scheint das Eu 3+ ‐Ion in den festen Proben eine niedrigere Lagesymmetrie und eine stärkere Wechselwirkung mit dem Liganden aufzuweisen als in den flüssigen. Für eine hydratisierte Eu 3+ ‐Spezies würde man ein erheblich geringeres Intensitätsverhältnis und einen Asymmetriefaktor von etwa 0.63 erwarten 23. Schon vor längerem hat man bemerkt, dass Wasser, das in die Koordinationssphäre des oxophilen Lanthanoid‐Kations eindringt, die Lumineszenz des Lanthanoids in ionischen Flüssigkeiten entscheidend beeinflusst.…”

Luminescent Materials of Europium(III) Coordinated by a Terpyridine‐Functionalized Poly(Ionic Liquid)

“…The intensity of the 5 D 0 → 7 F 2 transition is much higher than that of the 5 D 0 → 7 F 1 transition, and the intensity ratio of the 5 D 0 → 7 F 2 and 5 D 0 → 7 F 1 transitions is 5.42, which implies that the coordination environment of the Eu 3+ ions is devoid of an inversion center 21. In fact, the ratio is approximately 0.63 for a hydrated Eu 3+ species 62. The coordination of terpyridine in the polymer to Eu 3+ ions results in the repulsion of water molecules from the coordination sphere, and, as a consequence, this causes the remarkable changes in the intensity ratio of the 5 D 0 → 7 F 2 and 5 D 0 → 7 F 1 transitions.…”

“…[61] The molecular weight distributions of Terpy-PIL were determined by gel-permeation chromatography (GPC) [M n (GPC) = 63939 g/mol, M w /M n = 1.75]. [62] The coordination of terpyridine in the polymer to Eu 3+ ions results in the repulsion of water molecules from the coordination sphere, and, as a consequence, this causes the remarkable changes in the intensity ratio of the 5 D 0 Ǟ 7 F 2 and 5 D 0 Ǟ 7 F 1 transitions. Thermogravimetric analyses were performed to determine the thermal stability of the Terpy-PILs, and the TG curves are shown in Figure 5.…”