Pulse Radiolysis Studies. VI. The Lifetimes of Aromatic Anions in the Aliphatic Alcohols

The formation and the lifetimes of several aromatic anions in irradiated solutions of arenes in the aliphatic alcohols have been investigated by the pulse radiolysis technique. The aromatic anions show a fast decay which follows a first-order rate law. The absolute rate constants for this decay, suggested to be a proton transfer from the alcohol, arene−+ROH=arene H·+RO−,have been determined for four alcohols and three aromatic anions. The rate constants, which are found to be in the order CH3OH>C2H5OH≅C3H7OH>(CH3)2CHOH, show a close correlation with other measurements of the acidity of the alcohols. The absolute rate constants have also been determined for the reaction of several aromatic anions with hydrogen ion, arene−+ROH2+=arene H·+ROH,and for the attachment reaction of the solvated electron in ethanol, esol−+arene=arene−.