Stability of [MeBu₃N][Tf₂N] under gamma irradiation

Abstract

The stability of the ionic liquid [MeBu3N][Tf2N], dry or after contact with water (where [MeBu3N]+ is the methyltributylammonium cation and [Tf2N](-) is the bistriflimide anion), was studied under 137Cs gamma irradiation in argon and in air. In a quantitative study with an absorbed dose of 2 MGy this ionic liquid was highly stable regardless of the radiolysis conditions. The radiolytic disappearance yields determined by ESI-MS were -0.38 and -0.25 micromol J(-1) for the cation and anion, respectively. ESI-MS, NMR, and liquid chromatography coupled with ESI-MS identified a large number of degradation products in very small quantities for the same dose. The cation radicals were formed by the loss of a Bu group, the Me group, or two H atoms to form a double bond with the butyl chain. Radiolysis of the anion produced mainly F and CF3 radicals. The anion radicals recombined with the cation to form a wide range of secondary degradation products regardless of the radiolysis conditions.

Reactivity Towards Europium(III) of the Radiolysis Products of the Ionic Liquid 1‐Methyl‐3‐butyl‐1H‐imidazolium Bis[(trifluoromethyl)sulfonyl]amide (C4‐mimTf2N) and Effect of Water: A TRLFS (Time‐Resolved Laser‐Induced Fluorescence Spectroscopy) Preliminary Study

“…It has been shown [23] that in the case of fast excited-state chemistry, lifetimes merge so that the second component, characterized by t 2 and I 2 and an individual spectrum as displayed in Fig. 5 [6]. To detect and characterize radiolysis products by either NMR or ESI mass spectrometry, requested minimum doses were in the range of 450 kGy [5].…”

“…Actually, a significant darkening of the ILs under investigation has been reported, which is attributed to the appearance of stable radiolytic products in very low yields but presenting a very high molar absorption [4] [5]. Although these radiolytically stable products accumulate in solution linearly as a function of the irradiation dose, their precise chemical determination remains a difficult task, owing to their diversity and very low individual formation yields [5] [6]. Interestingly, it has been shown that the presence of H 2 O has no effect on the radiolytic-darkening kinetics [5] and that the degradation products are the same whatever the chemical conditions (presence or absence of air or H 2 O) [6].…”

“…Although these radiolytically stable products accumulate in solution linearly as a function of the irradiation dose, their precise chemical determination remains a difficult task, owing to their diversity and very low individual formation yields [5] [6]. Interestingly, it has been shown that the presence of H 2 O has no effect on the radiolytic-darkening kinetics [5] and that the degradation products are the same whatever the chemical conditions (presence or absence of air or H 2 O) [6]. By comparison with the radiolytic stability of tributyl phosphate (TBP) in kerosene, which is the usual industrial organic solution used to perform the liquid/liquid extraction/ partitioning of used nuclear fuels, it is concluded that ILs could be suitable media for the radiochemical treatment of nuclear waste.…”

Nanoparticle Preparation in Room-Temperature Ionic Liquid under Vacuum Condition

“…As a typical example, variation in UV-vis spectra of the RTILs with 0.5 mmol L -1 NaAuCl 4 ·2H 2 O after accelerator electron beam irradiation is shown in Fig. 8 (Bossé et al, 2008;Behar et al, 2001;Grodkowski et al, 2002;Shkrob et al, 2009), it is highly likely that radiochemically-unstable RTIL tends to generate Au nanoparticles. TEM observation revealed that the Au nanoparticles prepared in the experiments using the [BuMeIm][Tf 2 N] solution had mean particle size of 26.4 nm at 20 kGy irradiation and 7.6 nm at 6 kGy.…”

Changes of the near-surface chemical composition of the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide room temperature ionic liquid under the influence of irradiation

“…23,24 During the degradation of the anion mainly F, CF 3 and CF 3 SO 2 radicals are produced. [23][24][25] The purpose of this work is to investigate the influence of the commonly used monochromated and non-monochromated AlKa radiation on [EMIm]Tf 2 N. Therefore the IL is irradiated for five days in the case of monochromated X-rays and for over 12 hours in the case of non-monochromated AlKa. The observed changes in the spectral features are discussed in detail.…”