Polarizability and abnormal infrared spectra of molecules adsorbed on metal nanostructured surfaces

Abstract:

Based on the experimental results of abnormal infrared effects (AIREs) for molecules adsorbed on transition-metal nanostructured surfaces, the interactions and the polarizability of the adsorbed molecules are analyzed theoretically. By numerical simulations, the normal absorption spectrum, the Fano-like bipolar spectrum and the anti-absorption spectrum of the adsorbed CO molecules are obtained respectively. The results show that the adsorbed molecules on a metal nanostructured surface can accumulate together dues to the effect of local external electric field, which leads to a change in imaginary part of the molecular polarizability within a certain range of frequency, and even a negative value may appear.