Date: April 23, 2010
Creator: Santagata, Nancy M.; Lakhani, Amit M.; Davis, Bryce F.; Luo, Pengshun; Buongiorno Nardelli, Marco & Pearl, Thomas P.
Description: Article on chiral steering of molecular organization in the limit of weak adsorbate-substrate interactions. Abstract: The influence of intermolecular interactions involving molecular chiral centers on two-dimensional organization in the limit of a weak adsorbate-surface interaction has been studied with low-temperature scanning tunneling microscopy (STM) and density functional theory (DFT). A model system composed of a chiral organic molecule, tartaric acid, and an inert metallic surface, Ag(111), was employed. Dual component films formed from the serial deposition of (S,S)- and (R,R)-tartaric acid enantiomers onto this surface exhibit homochiral domain formation as revealed by molecularly resolved STM images. In contrast, a unique tartaric acid enantiomeric heteropair is experimentally and computationally verified as the basis unit of films formed via the deposition of both enantiomers simultaneously from a racemic (1:1) mixture. The molecular adsorption geometry relative to the Ag(111) lattice in both enantiomerically pure and racemic domains is determined primarily by the interaction of chiral centers between nearest neighbors.
Contributing Partner: UNT College of Arts and Sciences