Study of the oxidation mechanisms associated to new dimeric and trimeric esters of ferulic acid

Abstract The electrochemical behaviour of new ferulic acid derivatives, three dimeric and one tripodal esters as well as the monomeric benzylic ester, is described. All of them follow an ECE (electrochemical–chemical–electrochemical) oxidation mechanism. Electrografting processes were observed too, except in the case of the monomeric ester. Interestingly, topology seems to play an important role in their capacity of being adsorbed by the electrode, which suggest that a greater reactivity of the bi - and tri - radicals, probably generated during the first steps of electrochemical oxidation of this type of compounds or an increase of the van der Waals interactions between huge molecules and the electrode surface, could be the main responsible. In addition, electrodonating power, as that defined within the density functional theory, was estimated for the benzylic ester, one dimeric ester, the tripodal ester, and the ferulic acid. This quantity was compared with the corresponding experimental values of the oxidation potential. Results show that monomers are more effective for the process of donating electrons; however, a higher number of ferulic units increases the ability of the bis and tris structures to increase their electrodonating power.