Three-dimensional hydrogen bonding between Landers and planar molecules facilitated by electrostatic interactions with Ni adatoms.

Using a combination of UHV-STM and molecular mechanics calculations, we investigate the surface self-assembly of a complex multi-component metal-molecule system with synergistic non-covalent interactions. Hydrogen bonding between three-dimensional Lander-DAT molecules and planar PTCDI molecules, adsorbed closer to the surface, is found to be facilitated by electrostatic interactions between co-adsorbed Ni adatoms and the flexible molecular DAT groups.

Selection of conformational states in self-assembled surface structures formed from an oligo(naphthylene-ethynylene) 3-bit binary switch.

Supra-molecular self-assembly on surfaces often involves molecular conformational flexibility which may act to enrich the variation and complexity of the structures formed. However, systematic and explicit investigations of how molecular conformational states are selected in surface self-assembly processes are relatively scarce. Here, we use a combination of high-resolution scanning tunneling microscopy and Density Functional Theory (DFT) calculations to investigate self-assembly for a custom-designed molecule capable of assuming eight distinct surface conformations (four enantiomeric pairs).

Bicomponent hydrogen-bonded nanostructures formed by two complementary molecular Landers on Au(111).

The co-adsorption of two molecular Landers equipped with functional groups capable of forming a complementary triple hydrogen-bonding motif is investigated with scanning tunneling microscopy and molecular mechanics calculations. Surprisingly, the anticipated complementary motif is not realised in 2-D terrace structures, but is observed in 1-D structures at step edges where molecular conformational flexibility is confined.

Water clustering on nanostructured iron oxide films.

The adhesion of water to solid surfaces is characterized by the tendency to balance competing molecule-molecule and molecule-surface interactions. Hydroxyl groups form strong hydrogen bonds to water molecules and are known to substantially influence the wetting behaviour of oxide surfaces, but it is not well-understood how these hydroxyl groups and their distribution on a surface affect the molecular-scale structure at the interface. Here we report a study of water clustering on a moiré-structured iron oxide thin film with a controlled density of hydroxyl groups.

Chiral induction with chiral conformational switches in the limit of low "sergeants to soldiers" ratio.

Molecular-level insights into chiral adsorption phenomena are highly relevant within the fields of asymmetric heterogeneous catalysis or chiral separation and may contribute to understand the origins of homochirality in nature. Here, we investigate chiral induction by the "sergeants and soldiers" mechanism for an oligo(phenylene ethynylene) based chiral conformational switch by coadsorbing it with an intrinsically chiral seed on Au(111). Through statistical analysis of scanning tunneling microscopy (STM) data, we demonstrate successful chiral induction with a very low concentration of seeding molecules down to 3%.