The adsorption of achiral meso-tartaric acid on the copper(1 1 0) surface leads to 2D-enantiomorphous structures, observable as mirror domains in low-energy electron diffraction (LEED). The reason for this 2D-enantiomorphism is explained by adsorptioninduced chirality in the molecular frame combined with a lateral separation of the resulting two enantiomers on the surface. Co-adsorption of small amounts of (S,S)- or (R,R)-tartaric acid, however, suppresses the formation of one enantiomorphous domain and drives the entire monolayer into homochirality. (c) 2005 Elsevier B.V. All rights reserved.