Functional group selective STM Imaging in self-assembled monolayers: Benzeneselenol on Au(111)

Well-Ordered Monolayer Growth of Crown-Ether Ring Molecules on Cu(111) in Ultra-High Vacuum: An STM, UPS, and DFT Study

“…The growth of organic films by molecular evaporation and deposition on atomically clean substrates in ultrahigh vacuum (UHV) has been studied intensively in the last decades. − UHV growth has several advantages with respect to chemical growth methods such as drop-casting a molecular solution on the substrate in air. − First, contamination of the film with solvent residue, a common problem with solution-based processes, is excluded in UHV. Second, the formation of well-ordered molecular arrays can be controlled more easily in molecular beam epitaxy under UHV conditions, because of the cleanliness of the substrate and control of deposition rate and substrate temperature.…”

Polymorphism and Building‐Block‐Resolved STM Imaging of Self‐Assembled Monolayers of 4‐Fluorobenzenemethanethiol on Au(111)

“…One of representative examples is the occurrence of two distinct tunneling pathways for the cis‐conformers in the SAMs of 4‐(biphenyl‐4‐ylazo)‐biphenyl‐4‐thiol on Au(111), which allowed to monitor UV‐vis triggered isomerization of these molecules with atomic precision [19] . In another study, by the appearance of two specific spots in the STM images, it was possible to distinguish between the selenium headgroup and the molecular backbone of benzeneselenol molecules assembled on Au(111) [2g] . Finally, using a sophisticated combination of several imaging modes, it was possible to image selectively the tail and anchoring groups in bicomponent alkanethiolate SAMs on Au(111).…”

“…It was, however, demonstrated that the performance of the respective devices is strongly influenced by the quality of the SAMs, including such parameters as their morphology, packing density, molecular orientation, and structural order [7] . Consequently, these parameters were specifically addressed in the dedicated experiments, with scanning tunneling microscopy (STM) being a particular useful tool to study molecular structure [2g,8] . It has then been found that the self‐assembly of fluorine‐decorated molecules, performed usually within the standard immersion procedure, frequently yields SAMs of low structural quality.…”

Odd–even effects in aryl-substituted alkanethiolate SAMs: nonsymmetrical attachment of aryl unit and its impact on the SAM structure

“…The substantial mismatch between the Au(111) substrate lattice and the preferred lattice of the aromatic moieties explains the high density of translational domains previously found for conjugated, purely aromatic thiol SAMs, such as anthracene thiol monolayers. [35][36][37][38][39] The interpretation of the STM images for the b phase at n = 2 was complicated by the fact that the observed protrusions do not lay strictly along the molecular rows (such as along line A). Additionally, it was found that the distances between the neighboring protrusions along the molecular rows (line A) and perpendicular to these rows (line B) vary between 4.8 and 5.3 Å and 9.7 to 10.5 Å, respectively.…”