Free radicals interacting with Cu, Ag and Au clusters

We investigated free radical scavenger capacity of small neutral Cu, Ag and Au clusters (Cu, Ag and Au up to ten atoms, and Au-20), using three molecules (OH, (OOH)-O-center dot, (OCH3)-O-center dot) and two reaction mechanisms (Electron Transfer and Radical Adduct Formation). Principally this indicates that metal clusters are good free radical scavengers. They are good electron donors and the radical adduct formation reaction is thermodynamically feasible. Here, we show how Molecular Electrostatic Potential is very useful for determining the active site of the cluster in terms of interaction with the free radical. This investigation affirms that free radicals interact with the balanced electron density zone of the cluster. This may be very important for further studies that contemplate more than one free radical bonded to the metal clusters. These findings should serve as a significant guide for experimentalists when attempting to analyze the effectiveness of small Cu, Ag and Au clusters, as antioxidant materials. (C) 2017 Elsevier B.V. All rights reserved.