With the getting smaller of traditional electron devices and the advancement of nanotechnology and microfabrication, using molecules as components in atomic-scale circuits has become an attractive field and nanomaterials have become one of the most dazzling stars in the twenty-first century. β-Dicarbonyl compounds, with at least one a-hydrogen, are capable to display a keto–enol tautomerism as illustrated in Fig. 1. The cis-enol forms of β-dicarbonyl compounds are engaged in an IHB system and stabilized in a six-membered chelated ring [1–3]. The β-diketone compounds with at least one α-hydrogen are capable to display keto-enol tautomerism. Using nonequilibrium Green’s function formalism combined first-principles density functional theory; we study the transport properties of acetylacetone as a molecular switch. Three different adsorption types including top, bridge, and hollow were investigated. The I–V characteristics, differential conductance, on-off ratio, electronic transmission coefficients, HOMO–LUMO gaps and effect of electrode materials Y (Y=Au, Ag, and Pt) on electronic transport corresponding to the keto and enol forms through the molecular devices are discussed in detail. It was found that the best switching behavior performance happens in the gold electrode. Based on data when the enol form transforms to the keto form, there is a switch from on state to the off state (low resistance switches to high resistance).

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