(455a) Density Functional Theory Calculations Of Adsorption Of Chiral Modifiers On Pd(111)

Chiral modification of achiral metal catalysts with chiral auxiliary molecules is of great interest in the development of enantioselective heterogeneous catalysts. The source of the desired enantioselectivity lies in the interaction between the modifier and reactant. Characterizing these interactions requires an understanding of the local adsorption geometry of the template molecule. Amino acids have been investigated as a potential class of chiral modifiers. Previous experimental studies demonstrated that glycine is adsorbed on the Cu(100) and Cu(110) surfaces in its dehydrogenated form, NH2CH2COO, at room temperature. In contrast, recent X-ray Photoelectron Spectroscopy experiments indicate zwitterionic adsorption of glycine to Pd(111). Using Density Functional Theory, we have studied the adsorption of glycine on Pd(111), Cu(100) and Cu(110) to examine this apparent difference in chemical states on these surfaces.