Charge response study of the toluene-[V 2O 5] chemisorption clusters: Two reactant approach

Abstract

Using the charge sensitivity analysis in the atomic resolution the shifts in electron populations of constitutent atoms due to the intra-reactant polarization (P), inter-reactant charge transfer (CT), and the resulting overall (P + CT) patterns, are compared for alternative perpendicular and parallel chemisorption systems including toluene and the two (010)-layer, nearly stoichiometric V 36O 98 cluster. At each level of description a relative role of the diagonal (intra-reactant) and off-diagonal (inter-reactant) terms is examined. These isoelectronic (in situ) diagrams are supplemented by the global Fukui function diagrams, characterizing the open chemisorption system as a whole, in contact with the external electron reservoir. The in situ charge reconstruction patterns are predicted to be strongly localized in the chemisorption region, while the global Fukui function diagrams are delocalized throughout the whole cluster. In most cases the total isoelectronic responses are dominated by the diagonal contributions of the adsorbate and the off-diagonal component of the surface cluster. The in situ reactivity information is used to probe the adsorbate activation patterns and surface reconstruction trends for the eight most important (perpendicular and parallel) molecular chemisorption arrangements. The external CT data similarly reflect upon changes in the electronic/bond structure induced by the inflow/outflow of electrons to/from the chemisorption system, thus providing a qualitative information about the influence of the CT involving the cluster environment upon the chemisorption complex.