Quantum chemical study of surface reactions of glycine on the Si(1 0 0)-2 × 1 surface

Glycine, a polyfunctional molecule, can attach to the Si(1 0 0)-2 × 1 surface via N–H dissociation, O–H dissociation and CO [2 + 2] cycloaddition. Density functional theory simulations are performed to investigate the reaction mechanisms of glycine on the bare Si(1 0 0)-2 × 1 surface and probe the factors that control the competition and selectivity of organic functionalization on the clean Si(1 0 0)-2 × 1 surface. Our calculations indicate that the reaction pathway via O–H dissociation is overwhelmingly favored in both thermodynamic factors and kinetic factors. The dissociation can occur on a single dimer or across two adjacent dimers along a dimer row. Some rearrangements after the dissociation of O–H bond are also described.