Reactions of Aromatic Bifunctional Molecules on Silicon Surfaces: Nitrosobenzene and Nitrobenzene

Abstract

Chemical control of interfaces formed on silicon surfaces is important for many practical applications. In this work, the reaction of nitrosobenzene with a clean Si(100)- 2 × 1 surface by [2 + 2] cycloaddition at room temperature is investigated. This reaction is compared to the 1,3-dipolar cycloaddition reaction of nitrobenzene on the same surface and to the cyclocondensation reaction of nitrobenzene with hydrogen-terminated Si(100) surfaces. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) methods were used for this study. For both nitrosobenzene and nitrobenzene on Si(100)- 2 × 1, oxygen migrates subsurface, despite substantial kinetic barriers. The effects of oxygen migration are addressed by combining DFT cluster modeling and XPS in the N 1s region. The reaction pathways of these nitrogen-containing bifunctional molecules on a clean Si(100)- 2 × 1 surface lead to the phenylnitrene adduct as the dominant surface species, while ...