Front Cover: Molecular chirality at surfaces (Phys. Status Solidi B 11/2012)

Abstract

Chirality is ubiquitous in our world, but only during the last two decades the role it plays in two-dimensional systems has attracted the interest of surface scientists. The cover image - an adaptation from a scanning tunneling micrograph - shows a handed pinwheel pattern of six helical (M)-heptahelicene molecules on a copper(111) surface. Each “mountain” represents a single left-handed molecule. The right-handed (P)-enantiomer forms the corresponding mirror-image motif. Such transfer of handedness from single molecules into self-assembled supramolecular structures is one example of how molecular structure affects the shape of assemblies, not only on surfaces, but even up to crystal morphology. The Review Article by Karl-Heinz Ernst on pp. 2057–2088 gives a topical overview of different aspects of molecular chirality at surfaces and introduces principles of mirror symmetry breaking upon adsorption and two-dimensional self-assembly. The article gives also a historical view on chirality and different definitions available. Main topics are chiral and prochiral molecules at surfaces, amplification due to small chiral bias, chiral restructuring due to adsorption, intrinsically chiral surfaces and chiral switching.