Addition Reaction of Nitrones on the Reconstructed Si(100)-2 × 1 Surface

The reaction of nitrone, N -methyl nitrone, and their hydroxylamine tautomers (vinyl-hydroxylamine and N -methyl vinyl-hydroxylamine) on the reconstructed Si(100)-2 × 1 surface has been investigated by means of hybrid density functional theory (B3LYP) and Møller-Plesset second-order perturbation (MP2) methods. The calculations predicted that both of the nitrones should react with the surface dimer via facile concerted 1,3-dipolar cycloaddition leading to 5-member-ring compounds. The reaction of hydroxylamine tautomers on the Si(100) surface follows π-complex (intermediate) mechanism. For the reaction of N -methyl vinyl-hydroxylamine, the π-complex intermediate undergoes [2+2] cycloaddition leading to a 4-member-ring compound. But in the reaction of vinyl-hydroxylamine, the intermediate undergoes H-migration reaction (“ene” reaction) resulting in the oxime-terminated Si surface. All the surface reactions result in the hydroxyl-terminated silicon surfaces, which are very useful for the further modification of the semiconductor.