Pulse radiolysis studies of intermediates derived from p ‐terphenyl in the oxygenated methyltributylammonium bis[(trifluoromethyl)sulfonyl]imide ionic liquid

Radiation‐induced processes in oxygenated ionic liquid (IL) methyltributylammonium bis[(trifluoromethyl)sulfonyl]imide ([MeBu 3 N][NTf 2 ]) solutions containing p ‐terphenyl (TP) were investigated by the nanosecond pulse radiolysis with UV‐vis detection. The transient absorption spectra generated in these solutions were assigned to radical anions (TP •− ), radical cations (TP •+ ), and triplet excited states ( 3 TP*). Saturation of [MeBu 3 N][NTf 2 ] solutions with oxygen (O 2 ) efficiently eliminates solvated electrons ( e solv − ); however, it does not decrease significantly the radiation chemical yield of TP •− , which are mainly formed in a reaction of TP with presolvated electrons ( e presolv − ). On the other hand, the lifetime of TP •− decreases significantly due to their reaction with O 2 . The TP •+ is formed in a reaction of electron‐deficient centers of the IL (IL ⊕ ) with TP. Their radiation chemical yield and lifetime are not affected by the presence of O 2 ; however, they are decreased by the presence of triethylamine (TEA). The 3 TP* are formed in a reaction of excited states of ionic liquid (IL*) with TP. The presence of O 2 and TEA effectively eliminates 3 TP* in the time domain >1 μs.