Adsorption of phenylacetylene on Si(100)-2×1: Reaction mechanism and formation of a styrene-like π-conjugation system

Abstract

The interactions of phentylacetylene and phenylacetylene-α-d1 with Si(100)-2×1 have been studied as a model system to mechanistically understand the adsorption of conjugated π-electron aromatic substitutions on Si(100)-2×1. Vibrational signatures show that phenylacetylene covalently binds to the surface through a [2 +2]-like cycloaddition pathway between the external CCC and Si=Si dimer, forming styrene-like conjugation structure which was further supported by the chemical-shift of C 1s core level. These experimental results are consistent with the density-functional theory [B3LYP/6-311//+G(d)] calculations. The resulting styrene-like conjugation structures may possibly be employed as an intermediate for further organic syntheses and fabrication of molecular architecture for modification and functionalization of Si surfaces, or as a monomer for polymerization on Si surfaces.