Voltammetric determination of electron transfer kinetic parameters in hydroquinone-terminated self-assembled monolayers on gold

This paper reports the electron tunneling constant (beta) and distance depe ndence of the long range electron transfer kinetic parameters in the 2-(n-m ercaptoalkyl)hydroquinone (abbreviated as H(2)Q(CH2)nSH, where n = 1, 4, 6, 8, and 10) self-assembled monolayers (SAMs) on gold electrodes in acidic s olution. A logarithmic dependence of the heterogeneous electron transfer ra te constant for the redox reaction of hydroquinone (H(2)Q) on the thickness of the monolayer was obtained and the beta value in the H(2)Q SAM system w as determined to be (0.99+/-0.06) per methylene group in the alkyl chain sp acer. (C) 1999 Elsevier Science S.A. All rights reserved.