The structure of [Bmim]2Cu Cl4 ionic liquids(Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2 O and C2H5 OH was investigated using X-ray absorption fine structure(XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2Cu Cl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2 O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2Cu Cl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]2Cu Cl4/C2H5 OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2Cu Cl4. The structure of [Bmim]2Cu Cl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.
Bis(2-propyloxy)calix[4]crown-6 (BPC6) is an effective separation agent for cesium removing from spent nuclear fuel. The study on radiolytic behavior of BPC6 itself under γ-irradiation was required for evaluating its feasibility of practical application. It was found that BPC6 exhibited excellent radiation stability at dose less than 100 kGy. However, the isopropyl groups in BPC6 under- went oxidation and dealkylation to form carbonyl groups and phenolic hydroxyl groups at dose above 300 kGy, respectively. When the dose was more than 1000 kGy, the ring opening of crown ether structure of BPC6 resulted in the formation of phenolic hydroxyl groups as well. The formation of radiolytic products containing phenolic hydroxyl groups during the irradiation of BPC was confirmed by using FeCl 3 as a probe. Combining with the radiolytic behavior of two model chemicals (1-isopropoxybenzene and benzo-18-crown-6 ether), the radiolytic behavior and mechanism of BPC6 under -irradiation was testified further.
AO YinYongPENG JingZHANG YouWeiYUAN LiYongYU ChuHongLI JiuQiangZHAI MaoLin
The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by19 F NMR(G(F-) = 0.14 μmol/J, G(HOP(O)F2) = 0.053 μmol/J). Compared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.
