Reactions of solvated electrons with imidazolium cations in ionic liquids

金沢大学理工研究域自然システム学系We examined formation of solvated electrons in several ionic liquids composed of ammonium, pyrrolidinium and piperidinium cations by observing absorption spectra in the visible and near-infrared regions using pulse radiolysi. We also examined reactions of the solvated electrons with imidazolium cations in the ionic liquids. The reaction rate constants were an order of magnitude faster than the diffusion-limited rate calculated from the viscosity. The electrons before full solvation (dry electrons) reacted efficiently with the imidazolium cations. These observations suggest that the electrons in the ionic liquids can move easily before solvation. The scavenging of the dry electron by the imidazolium cation was also examined using C2-alkylated-imidazolium cations. It is found that the alkylation of imidazolium suppresses the reactivity with the dry electron. © 2008 Elsevier Ltd. All rights reserved

Photo-detrapping of solvated electrons in an ionic liquid

金沢大学理工研究域自然システム学系We studied the dynamics of photo-detrapped solvated electrons in the ionic liquid trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI) using laser flash photolysis. The solvated electrons were produced by the electron photodetachment from iodide via a 248 nm KrF excimer laser. The solvated electron decayed by first-order kinetics with a lifetime of about 240 ns. The spectrum of the solvated electron in the ionic liquid TMPA-TFSI is very broad with a peak around 1100 nm. After the 248 nm pulse, a 532 nm pulse was used to subsequently detrap the solvated electrons. After the detrapping pulse, quasi-permanent bleaching was observed. The relative magnitude of the bleaching in the solvated electron absorbance was measured from 500 to 1000 nm. The amount of bleaching depends on the probe wavelength. The fraction of bleached absorbance was larger at 500 nm than that at 1000 nm, suggesting that there are at least two species that absorb 532 nm light. We discuss the present results from viewpoint of the heterogeneity of ionic liquids. © 2009 Elsevier Ltd

Studies on Early Processes in Radiation Cemistry by Means of ESR Spectroscopy and Picosecond Pulse Rodiolysis

報告番号: 乙05606 ; 学位授与年月日: 1981-03-20 ; 学位の種別: 論文博士 ; 学位の種類: 工学博士 ; 学位記番号: 第5606号 ; 研究科・専攻: 工学系研究

ESR法及びピコ秒パルスラジオリシス法を用いた放射線化学初期過程の研究

University of Tokyo (東京大学