A dynamic surface prepared by electrochemical triggering of substituted methoxyphenol-terminated self-assembled monolayers for multi-functional purposes

We devised a methoxyphenol thiol derivative with an electron-withdrawing (-CHO) and an electron-donating (-CH2OH) substituent for the preparation of a dynamic surface that can be used for multi-functional purposes. This molecule was electrochemically activated to an o-quinone form by the oxidative triggering through demethoxylation, followed by hydroxylation on para position upon potential cycling whose rate depended on the nature of substituents. An eiectron-withdrawing substituent facilitated nucleophilic addition of water, forming a 1,2,5-trihydroxy form, and only para-hydroquinone underwent a redox reaction. An electron-donating substituent, however, was not able to activate this process, leaving behind only an ortho form. The o-quinone showed catalytic activity toward ascorbic acid and NADH oxidation. (C) 2009 Elsevier B.V. All rights reserved.