Effects of Quaternary Ammonium Salts on Reactions of Aromatic radical Anions Formed in Tetrahydrofuran by Pulse Radiolysis

Article abstract of DOI:10.1021/j150655a037

Pulse radiolysis of biphenyl (BP) and pyrene (Py) in tetrahydrofuran (THF) solution was carried out in the presence of various kinds of quaternary ammonium salts, such as Bu4NPF6, Bu4NBF4, Bu4NI, BzMe3NPF6 and PhMe3NPF6 (Bu, butyl; Me, mthyl; Bz, benzyl; and Ph, phenyl).The decay behaviors of the radical anions, BP^-. and Py^-., are significantly affected by the addition of the salts.The anions of the salts, PF6^-, BF4^-, and I^-, are considered to form ion pairs with the solvent counterions, THF(H⁺), resulting in a retardation of the neutralization reactions.The rate constants for the neutralization reactions have been determined in the absence and presence of Bu4NPF6.The addition of BzMe3NPF6 (or PhMe3NPF6) accelerates the decay of BP^-. and retards the decay of Py^-., depending on the rates of reactions of the radical anions with BzMe3N⁺ (or PhMe3N⁺).The reactivity of BP^-. in the electron transfer to Py seems to be reduced in the presence of Bu4NPF6.The effect of Bu4N⁺ on the reactions of the radical anions is discussed.