On-Surface Synthesis of Self-Assembled Monolayers of Benzothiazole Derivatives Studied by STM and XPS

Abstract

On-surface synthesis has gradually become a prevalent approach to constructing two-dimensional functional monolayers on various substrates. In the present work, the synthesis of self-assembled monolayers (SAMs) of benzothiazole derivatives was conducted at the liquid/solid interface for the first time. Two kinds of nanostructures were achieved on the highly oriented pyrolytic graphite (HOPG) surface via the condensation reaction between aromatic aldehyde derivatives and 2-aminothiophenol (ATP). The formation of thiazole-based self-assemblies was revealed by scanning tunneling microscopy (STM) and further confirmed by X-ray photoelectron spectroscopy (XPS). The successful synthesis of the benzothiazole derivatives not only extends the scope of on-surface reactions but also can be applied in designing multifunctional SAMs at the interface.

On-Surface Self-Assembled Structural Transformation Induced by Schiff Base Reaction and Hydrogen bonds

“…33,34 During the on-surface reaction process, new molecules would be produced in situ and form new selfassembled architectures. 35,36 Thus, plentiful efforts have been made to investigate the on-surface synthesis of chemical molecules during these years, for example, the Schiff-based reaction, 37−39 Glaser reaction, 40−42 Ullmann coupling reaction, 43−45 photochemical reaction, 15,46 Knoevenagel reaction, 33 and so forth. 47 With the help of on-surface reactions, various self-assembled covalent structures have been successfully constructed on the 2D substrate.…”

“…It is necessary to note the balance is not immutable, and a series of elements will influence the self-assembled nanostructures, for instance, molecular concentration, light irradiation, temperature, solvent polarity, and so on. ,− Under some special circumstances, the self-assembled molecular structures could be transformed much more easily, such as the on-surface reaction. , In addition, the nanostructures formed by on-surface reaction are more thermodynamically and chemically stable and undergo the breakage and reformation of the covalent bonds. , During the on-surface reaction process, new molecules would be produced in situ and form new self-assembled architectures. , Thus, plentiful efforts have been made to investigate the on-surface synthesis of chemical molecules during these years, for example, the Schiff-based reaction, − Glaser reaction, − Ullmann coupling reaction, − photochemical reaction, , Knoevenagel reaction, and so forth . With the help of on-surface reactions, various self-assembled covalent structures have been successfully constructed on the 2D substrate. ,,− Furthermore, the intermediate products of the reaction are capable of being clearly detected by the actual-time and in situ STM characterization, which helps to elucidate the reaction principles of the molecular nanoarchitectures on the surface.…”

Self-Assembly of a Flexible Porphyrin Derivative Containing Tetra Isophthalic Acids and Host–Guest Interaction at the Liquid/Solid Interface

“…Scanning tunneling microscope (STM) has gained great attention in the field of surface analysis technology due to its advantages of atomic resolution and low requirements for the working environment. , The advent of STM enables us to observe the individual molecular arrangement on the surface/interface in three-dimensional (3D) space, as well as the chemical and physical information related to the surface electronic behaviors. Therefore, this paper uses STM to monitor the carboxylic porphyrin’s assembly morphology, which is regulated by hydrogen bonds.…”

Nanotribological Study of Supramolecular Template Networks Induced by Hydrogen Bonds and van der Waals Forces

“…A large amount of supramolecular assemblies of organic molecules (alkanes, porphyrin and phthalocyanine derivatives, peptides, etc. ) have been constructed on the surfaces of carbon-based materials and specific metals. − Therefore, although supramolecular assembly is not favorable for building “permanent” architectures, it could serve as a model with which to explore the intermolecular interaction mechanisms and structure–property relationship at the molecular level . Nevertheless, to the best of our knowledge, studies on the tribological behaviors of supramolecular assemblies are exceedingly rare. − In our previously reported work, the friction forces of the saccharic acid/pyridine (co-assembled) system were measured to be larger than those of the pristine saccharic acid (non-assembled) system, which revealed the effect of intermolecular interactions on the nanotribological properties of assembly systems .…”