A [4+2]-like cycloaddition of methyl methacrylate on Si(100)-2×1

Abstract

The attachment of methyl methacrylate (MMA) on Si(100)-2×1 was investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) calculations. The HREELS spectra of chemisorbed MMA show the disappearance of characteristic vibrations of C=O (1725 cm-1) and C(sp2)-H (3110, 1400, and 962 cm-1) coupled with the blue shift of the C=C stretching mode by 34 cm-1 compared to those of physisorbed molecules. These results clearly demonstrate that both C=C and C=O in MMA directly participate in the interaction with the surface to form a SiCH2C(CH3)=C(OCH3)OSi species via a [4+2]-like cycloaddition. This binding configuration was further supported by XPS, UPS, and DFT studies. © 2005 American Chemical Society.