Electrochemical grafting of heterocyclic molecules on glassy carbon and platinum using heteroaromatic iodonium salts or iodosubstituted heteroaromatics

Electrochemical grafting of aryldiazonium salts has been widely explored for functionalization of conducting surfaces with aromatic molecules. Unfortunately, heteroaromatic diazonium salts are highly unstable and decompose rapidly, precluding, in general, the use of such salts. We show here that pyridine and thiophene based iodonium salts along with iodo-substituted pyridine, thiophene, furan, and pyrrole may find use as suitable grafting agents. The precursors are much more stable than their diazonium analogs but the price to pay is a slower grafting process that takes place at a more extreme potential. The grafted films are characterized electrochemically and spectroscopically by XPS, IRRAS, and Raman. (C) 2018 Elsevier Ltd. All rights reserved.