Glycine adsorption on silicon (001)

Abstract

In this work we employ the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory, to investigate the dissociative adsorption process of glycine on the silicon surface. Our total energy calculations indicate that the chemisorption of the molecule is as follow. The gas phase NH 2 -C 2 H 2 -OOH adsorbs molecularly to the electrophilic surface Si atom and then dissociates into NH 2 -C 2 H 2 -OO and H, bonded to the electrophilic and nucleophilic surface silicon dimer atoms respectively, with an energy barrier corresponding to a thermal activation that is smaller than the usual growth temperature, indicating that glycine molecules will be observed in their dissociated states at room temperature. This picture is further support by our calculated vibrational modes for the considered adsorbed species.

Dissociative Adsorption and Thermal Evolution of Acetic Acid on Si(100)2×1: Surface-Mediated Formation of Ketene and Acetaldehyde from Unidentate and Bidentate Acetate Adsorbates

“…Surface reactions on Si(100)2×1 have been reported for many organic molecules with single or multiple functional groups, including unsaturated aliphatic hydrocarbons (ethylene, − acetylene ,− ), aromatic hydrocarbons (benzene − ), halogenated hydrocarbons, − amines , − amino acids, , carbonyl compounds (aldehyde, , ketone , ), alcohols, − and aliphatic and aromatic carboxylic acids (formic acid, − vinyl acetic acid, benzoic acid, , and 4-aminobenzoic acid). Among the wide range of organic functional groups, the carboxyl group is one of the key constituents of amino acids, the building blocks of peptides and proteins.…”

Glycine Adsorption on (101̅0) ZnO Surfaces

“…For this configuration, glycine binds to the substrate in a −COOH monodentate adsorption mode and dissociatively as one hydrogen atom migrates from the −COOH group to the surface oxygen site. Similar investigations on glycine adsorption on Si surfaces found a barrier height for dissociation of only 1 eV, suggesting that dissociation is likely to occur at room temperature. One of the carboxylic oxygens, O 1 , binds to the surface Zn atom with a bond length of 2.15 Å, whereas oxygen atom O 2 is equidistant from the surface Zn atoms at 2.28 Å.…”

Theoretical model of the interaction of glycine with hydrogenated amorphous carbon (HAC)

“…44,45 The full procedure used in this work is as follows. The 2 Â 1 (001) surface of silicon has been well characterized in previous investigations where silicon was modeled as a substrate for adsorptions of different species.…”

“…The 2 Â 1 (001) surface of silicon has been well characterized in previous investigations where silicon was modeled as a substrate for adsorptions of different species. 44,45 The full procedure used in this work is as follows. We have started by optimizing the Si unit cell, which yielded a lattice constant value of 5.423 Å and a d Si-Si value of 2.348 Å, very close to the experimental results of 5.43 Å and 2.35 Å respectively.…”