title: Homochiral conglomerates and racemic crystals in two dimensions: tartaric acid on Cu(110).
abstract: Two-dimensional lattice structures formed by racemic tartaric acid on a single crystalline Cu(110) surface have been studied and compared with the enantiopure lattices. At low coverage, the doubly deprotonated bitartrate species is separated into two-dimensional conglomerates showing opposite enantiomorphism. At higher coverage, however, a singly deprotonated monotartrate species forms a heterochiral, racemic crystal lattice. While the enantioseparated bitartrate system undergoes decomposition at the same temperature as the enantiopure system, the racemic monotartrate lattice has a lower thermal stability than the enantiopure lattice of identical periodicity and surface density. At monolayer saturation coverage, the pure enantiomers form a denser lattice than the racemate. This is in contrast to the three-dimensional tartaric acid crystals, where the racemate crystallizes in a lattice of higher density, which is also more thermally stable than the enantiopure tartaric acid crystals.
authors.affiliation: Nanoscale Materials Science, Swiss Federal Institute for Materials Science and Technology (EMPA), Dübendorf, Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Romer
authors.forename: Bahar
authors.initials: B
authors.lastname: Behzadi
authors.forename: Roman
authors.initials: R
authors.lastname: Fasel
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ernst