Preferential Sites for Adsorption of CO on Au-6 Clusters Using Density Functional Theory Based Reactivity Descriptors

摘要

Nanoarchitectonics of neutral Au-6 cluster upon addition and removal of one electron have been studied using density functional based reactivity descriptors. We studied the response of various sites of cationic, neutral and anionic Au-6 clusters towards impending electrophilic and nucleophilic attacks using DFT based local reactivity descriptors, viz, Fukui function for nucleophilic attack f(+) Fukui function for electrophilic attack f(-), relative nucleophilicity f(+)/f(-) and relative electrophilicity f(+)/f(-). Based on these parameters different types of unique atoms have been identified for each cluster. Reactivity predictions for the unique atoms of the minimum energy planar triangular Au-6 structure have been verified by using CO as a probe molecule. It has been found adsorption of CO molecules on gold cluster brings about structural changes in the cluster and that the CO molecule prefers the apex site for adsorption onto the triangular Au-6 cluster as compared to the mid site.