Pulse radiolysis studies on radiolytic behavior of ionic liquids of thiocyanate salts

Nagaishi, Ryuji ; Aoyagi, Noboru   ; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*

Radiolytic behavior of ionic liquids having thiocyanate ion as a constituent, of which the reactions with radiolysis products of water are well known, was studied by using the ns-pulse radiolysis technique to clarify the ionization sites and the presence of geminate radical formed together with electron in the liquids. The transient absorption of thiocyante dimer radical ion was observed in the liquids, and the rise was within the pulse width. The maximum absorbance of dimer in the liquids was equivalent to that in aqueous solutions, where the dimer is formed from the reaction of thiocyanate ion with OH radical, and increased with increasing the thiocyanate concentration in the liquids. These indicate that one of the ionization sites of liquids should be thiocyanate ion, leading to the formation of electron and thiocyanate radical. Difference in the radiolytic behavior between imidazolium and ammonium salts, and the ps-pulse radiolysis will be also discussed.