title: From Homochiral Clusters to Racemate Crystals: Viable Nuclei in 2D Chiral Crystallization.
abstract: The quest for enantiopure compounds raises the question of which factors favor conglomerate crystallization over racemate crystallization. Studying nucleation and crystal growth at surfaces with submolecular-resolution scanning tunneling microscopy is a suitable approach to better understand intermolecular chiral recognition. Racemic heptahelicene on the Ag(100) surface shows a transition from homochiral nuclei to larger racemic motifs, although the extended homochiral phase exhibits higher density. The homochiral-heterochiral transition is explained by the higher stability of growing nuclei due to a better match of the molecular lattice to the substrate surface. Our observations are direct visual proof of viable nuclei.
authors.affiliation: †Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Seibel
authors.affiliation: †Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland.
authors.forename: Manfred
authors.initials: M
authors.lastname: Parschau
authors.affiliation: †Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland.|‡Department of Chemistry, University of Zurich, 8057 Zürich, Switzerland.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ernst