title: Asymmetry induction by cooperative intermolecular hydrogen bonds in surface-anchored layers of achiral molecules.
abstract: The mesoscale induction of two-dimensional supramolecular chirality (formation of 2D organic domains with a single handedness) was achieved by self-assembly of 1,2,4-benzenetricarboxylic (trimellitic) acid on a Cu(100) surface at elevated temperatures. The combination of spectroscopic [X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS)], real-space-probe [scanning tunneling microscopy (STM)], and computational [density functional theory (DFT)] methods allows a comprehensive characterization of the obtained organic adlayers, where details of molecular adsorption geometry, intermolecular coupling, and surface chemical bonding are elucidated. The trimellitic acid species, comprising three functional carboxylic groups, form distinct stable mirror-symmetric hydrogen-bonded domains. The chiral ordering is associated with conformational restriction in the domains: molecules anchor to the substrate with an ortho carboxylate group, providing two para carboxylic acid moieties for collective lateral interweaving through H bonding, which induces a specific tilt of the molecular plane. The ease of molecular symmetry switching in domain formation makes homochiral-signature propagation solely limited by the terrace width. The molecular layer modifies the morphology of the underlying copper substrate and induces mum-sized strictly homochiral terraces.
authors.affiliation: Max-Planck-Institut für Festkörperforschung 70569 Stuttgart, Germany. alexd@fy.chalmers.se
authors.forename: Alexandre
authors.initials: A
authors.lastname: Dmitriev
authors.forename: Hannes
authors.initials: H
authors.lastname: Spillmann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stepanow
authors.forename: Thomas
authors.initials: T
authors.lastname: Strunskus
authors.forename: Christof
authors.initials: C
authors.lastname: Wöll
authors.forename: Ari P
authors.initials: AP
authors.lastname: Seitsonen
authors.forename: Magali
authors.initials: M
authors.lastname: Lingenfelder
authors.forename: Nian
authors.initials: N
authors.lastname: Lin
authors.forename: Johannes V
authors.initials: JV
authors.lastname: Barth
authors.forename: Klaus
authors.initials: K
authors.lastname: Kern