Surface Chemistry of Chiral Compounds on Chiral and Achiral Surfaces

This works aims to expand our understanding of amino acid surface chemistry on chiral and achiral metallic substrates. Both experimental and computational methods are employed to deepen our knowledge that relates the dependence of amino acid adsorption and decomposition kinetics on the chemical state, surface orientation, or external fields of the metal surface.

The thermal decomposition of L-aspartic acid (L-Asp) on Ni(100) reveals a more complex pathway than previously found on Cu surfaces. At low coverage, Asp undergoes an intra- and inter-molecular condensation/dehydration process. At high coverage, Asp adsorbs as aspartate along terrace sites and decomposes to produce CO₂, H₂, and CH₃C≡N. The use of isotopic labelling provided insights into the regiospecific origin of its decomposition products.The influence of an external magnetic field on the adsorption kinetics of Asp are investigated by exposing a flux of either L-Asp or co-dosing both L/D-Asp enantiomers on a Ni(100) surface either magnetized or non-magnetized. Both experimental studies indicate no kinetic anomalies due to surface magnetization.

Computational and machine learning methodologies are applied to investigate the dependence of surface orientation on the decomposition kinetics of tartaric acid (TA) on Cu. Lasso linear regression in conjunction with a normalized GCN density feature representation yields accurate halftime predictions for both L-/D-TA. The model predicts the Cu(61,21,10) surface as the most enantiospecific surface across all possible surface orientation. This modeling framework correlates surface structure with kinetic halftime and can guide the efficient experimental design and search of enantiospecific surfaces.Early work investigating the enantiospecific desorption of L-/D-lysine enantiomer on chiral and achiral Cu(3,1,17)^R&S RABiTs or an achiral Cu(100) RABiT appear with suggestions for future work discussed.