O. Pluchery et al., Hydrolysis of the 4-cyanopyridine on a Au(111) electrode studied by vibrational spectroscopies, ELECTR ACT, 46(28), 2001, pp. 4319-4329
The adsorption of 4-cyanopyridine on a Au(111) electrode is studied by cycl
ic voltammetry, FTIR and Sum Frequency Generation (SFG). This subject needs
insight because potential-dependent irreversible reactions occur on the el
ectrode. The present study is the continuation of a previous one which deal
t with the potential-dependent orientation of 4-cyanopyridine (4-CP) on Au(
111) electrodes. In this paper we are considering the hydrolysis of 4-CP in
to isonicotinamide occurring competitively to the reorientation of the 4-CP
molecule. This results in the dissociation of the CN group into CONH, We s
how that in a perchlorate supporting test electrolyte, the adsorbed cyanopy
ridine adlayer is progressively hydrolyzed when the electrode potential is
successively swept negatively then positively between - 0.8 and + 0.6 V (Ag
I AgCl). The product and the mechanism of the hydrolysis reaction are iden
tified thanks to the use of in situ FTIR. SFG spectroscopy is used in the 8
50-1100 cm(-1) range to address the question of the very slow kinetics of t
he reaction. (C) 2001 Elsevier Science Ltd. All rights reserved.