Pulse radiolysis study of formation of poly(4-vinylbiphenyl) anions in 2-methyltetrahydrofuran solution at 100–120 K

The reactions of poly(4-vinylbiphenyl) (denoted as PVB) polymers and biphenyl molecules with solvated electrons in the 2-methyltetrahydrofuran (MTHF) solvent have been studied at 100–120 K by electron-pulse radiolysis. The formation of PVB polymer anions as well as biphenyl anions was observed by the electron-pulse irradiation of the MTHF-PVB(or biphenyl) solution. The anions are formed by two processes; a rapid formation during the pulse irradiation (<20 ns) and a slow formation after the pulse irradiation. The slow formation is due to a diffusion-controlled reaction between solutes, such as PVB and biphenyl, and solvated electrons. It was found that the reaction efficiency, expressed in monomer unit, of PVB polymers is 1/27 of that of biphenyl molecules. The reaction radius for the electron capture reaction of PVB polymers is estimated as 200–370 A, which is much larger than the gyration radius (107 A) of polymer coils in MTHF solution.