Laser flash photolysis technique was employed to investigate the reactivity of hydrated electron (e(aq)(-)) toward a series of perfluorinated carboxylates, C nF2n+1COO- (n = 1, 3, 7), at 288 +/- 1 K in aqueous phase. It was demonstrated that the length -CnF2n+1 group exerted substantial influence on the rate constant. The second-order rate constants for e(aq)(-) with CF3COO-, C3F7COO-, C7F15COO- were estimated mated to be (1.9 +/- 0.2) x 10(6) M-1 s(-1) (mu = 0), (7.1 +/- 0.3) x 10(6) M-1 s(-1) (mu = 0) and (1.7 +/- 0.5) x 10(7) M-1 s(-1) (mu = 0.01 M), respectively. (c) 2007 Elsevier B.V. All rights reserved.