On-Surfaces Synthesis on Insulating Substrates

On-surface synthesis has attracted great attention in recent years due to its promising potential for creating functional structures on surfaces. An important aspect of on-surface synthesis is the capability to arrive at covalently linked thermally stable structures that offer the possibility for application even in harsh environments outside ultra-high vacuum conditions. Additionally, covalent linking allows for fabricating conjugated structures with superior electron transport properties. Especially, the latter is of tremendous interest when considering future applications in the field of molecular electronics. Having molecular electronics applications in mind explains the need for decoup…

Reversible and Efficient Light-Induced Molecular Switching on an Insulator Surface

Prototypical molecular switches such as azobenzenes exhibit two states, i.e., trans and cis, with different characteristic physical properties. In recent years various derivatives were investigated on metallic surfaces. However, bulk insulators as supporting substrate reveal important advantages since they allow electronic decoupling from the environment, which is key to control the switching properties. Here, we report on the light-induced isomerization of an azobenzene derivative on a bulk insulator surface, in this case calcite (101̅4), studied by atomic force microscopy with submolecular resolution. Surprisingly, cis isomers appear on the surface already directly after preparation, indi…

Substrate templating guides the photoinduced reaction of C60on calcite

cited By 7; International audience; A substrate-guided photochemical reaction of C60 fullerenes on calcite, a bulk insulator, investigated by non-contact atomic force microscopy is presented. The success of the covalent linkage is evident from a shortening of the intermolecular distances, which is clearly expressed by the disappearance of the moiré pattern. Furthermore, UV/Vis spectroscopy and mass spectrometry measurements carried out on thick films demonstrate the ability of our setup for initiating the photoinduced reaction. The irradiation of C60 results in well-oriented covalently linked domains. The orientation of these domains is dictated by the lattice dimensions of the underlying c…

ChemInform Abstract: On-Surface Reactions

From dewetting to wetting molecular layers: C60 on CaCO3(10 ̅14) as a case study.

We report the formation of extended molecular layers of C-60 molecules on a dielectric surface at room temperature. In sharp contrast to previous C-60 adsorption studies on prototypical ionic crystal surfaces, a wetting layer is obtained when choosing the calcite (CaCO3)(10 (1) over bar4) surface as a substrate. Non-contact atomic force microscopy data reveal an excellent match of the hexagonal lattice of the molecular layer with the unit cell dimension of CaCO3(10 (1) over bar4) in the [01 (1) over bar0] direction, while a lattice mismatch along the [(4) over bar(2) over bar 61] direction results in a large-scale moire modulation. Overall, a (2 x 15) wetting layer is obtained. The distinct…

Templatgesteuerte Photoreaktion von C60auf Calcit

Wir zeigen die photochemisch induzierte Reaktion von C60 auf dem Nichtleiter Calcit, die mit Nichtkontakt-Rasterkraftmikroskopie untersucht wurde. Die Bildung kovalenter Bindungen wird durch die Verringerung intermolekularer Abstande offensichtlich. Diese Interpretation wird zusatzlich durch UV/Vis- und Massenspektren an dicken Filmen gestutzt. Die Bestrahlung von C60 fuhrt zu wohlgeordneten, kovalent verknupften Domanen. Daruber hinaus wird die Orientierung der Domanen durch die Gitterdimensionen des Calcitsubstrats vorgegeben. Die Gitterfehlanpassung gezielt zu nutzen, um bewusst die Richtung der Reaktion zu beeinflussen, ist ein neuer Ansatz, um Reaktionen auf Oberflachen maszuschneidern…

Sequential and site-specific on-surface synthesis on a bulk insulator

cited By 15; International audience; The bottom-up construction of functional devices from molecular building blocks offers great potential in tailoring materials properties and functionality with utmost control. An important step toward exploiting bottom-up construction for real-life applications is the creation of covalently bonded structures that provide sufficient stability as well as superior charge transport properties over reversibly linked self-assembled structures. On-surface synthesis has emerged as a promising strategy for fabricating stable, covalently bound molecular structure on surfaces. So far, a majority of the structures created by this method have been obtained from a rat…

On-Surface Reactions

On-surface synthesis constitutes a rapidly growing field of research due to its promising application for creating stable molecular structures on surfaces. While self-assembled structures rely on reversible interactions, on-surface synthesis provides the potential for creating long-term stable structures with well-controlled properties, for example superior electron transport for future molecular electronic devices. On-surface synthesis holds the promise for preparing insoluble compounds that cannot be produced in solution. Another highly exciting aspect of on-surface synthesis is the chance to discover new reaction pathways due to the two-dimensional confinement of the reaction educts. In …