Adsorption of phenylacetylene on Si„100...-2Ã1: Reaction mechanism and formation of a styrene-like p-conjugation system

The interactions of phentylacetylene and phenylacetylene-a-d1 with Si(100)-231 have been studied as a model system to mechanistically understand the adsorption of conjugated p-electron aromatic substitutions on Si(100)-231. Vibrational signatures show that phenylacetylene covalently binds to the surface through a @2 12#-like cycloaddition pathway between the external CwC and SivSi 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//1G~d!# calculations. The resulting styrenelike 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.